enable support for JUnit/XUnit and JSON output

[jaypipes]

Adds a -o|--output CLI option to the gdt CLI tool that triggers output in either JUnit/XUnit:

$ gdt run --debug ../../chkk-io/readiness-checks/guided/addons/cert-manager/api.readiness-after14.yaml -oxunit
<?xml version="1.0" encoding="UTF-8"?>
<testsuites>
  <testsuite name="api.readiness-after14.yaml" time="2.885919111s" failures="0" errors="0" tests="6" timestamp="2025-12-09T14:39:15.621382231-05:00">
    <properties name="path" value="../../chkk-io/readiness-checks/guided/addons/cert-manager/api.readiness-after14.yaml"></properties>
    <testcases name="Cert Manager API Readiness Checks/ensure certificaterequest CRD installed" time="12.454946ms" status="ok">
      <system-out><![CDATA[[gdt] [Cert Manager API Readiness Checks/0:ensure certificaterequest CRD installed] using retry (exponential: true) [plugin default]
[gdt] [Cert Manager API Readiness Checks/0:ensure certificaterequest CRD installed] using timeout of 5s [plugin default]
[gdt] [Cert Manager API Readiness Checks/0:ensure certificaterequest CRD installed] kube.get: customresourcedefinitions/certificaterequests.cert-manager.io (non-namespaced resource)
[gdt] [Cert Manager API Readiness Checks/0:ensure certificaterequest CRD installed] spec/run: attempt 1 after 952ns ok: true
]]></system-out>
    </testcases>
    <testcases name="Cert Manager API Readiness Checks/ensure issuers CRD installed" time="9.552465ms" status="ok">
      <system-out><![CDATA[[gdt] [Cert Manager API Readiness Checks/1:ensure issuers CRD installed] using retry (exponential: true) [plugin default]
[gdt] [Cert Manager API Readiness Checks/1:ensure issuers CRD installed] using timeout of 5s [plugin default]
[gdt] [Cert Manager API Readiness Checks/1:ensure issuers CRD installed] kube.get: customresourcedefinitions/issuers.cert-manager.io (non-namespaced resource)
[gdt] [Cert Manager API Readiness Checks/1:ensure issuers CRD installed] spec/run: attempt 1 after 1.178µs ok: true
]]></system-out>
    </testcases>
    <testcases name="Cert Manager API Readiness Checks/cmctl check api" time="42.481764ms" status="ok">
      <system-out><![CDATA[[gdt] [Cert Manager API Readiness Checks/2:cmctl check api] using timeout of 10s [plugin default]
[gdt] [Cert Manager API Readiness Checks/2:cmctl check api] exec: cmctl [check api]
[gdt] [Cert Manager API Readiness Checks/2:cmctl check api] exec: stdout: The cert-manager API is ready
[gdt] [Cert Manager API Readiness Checks/2:cmctl check api] spec/run: single-shot (no retries) ok: true
]]></system-out>
    </testcases>
    <testcases name="Cert Manager API Readiness Checks/get webhook pod name" time="6.448293ms" status="ok">
      <system-out><![CDATA[[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] using retry (exponential: true) [plugin default]
[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] using timeout of 5s [plugin default]
[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] kube.get: pods (labels: app.kubernetes.io/component=webhook) (ns: cert-manager)
[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] save.vars: WEBHOOK_POD_NAME -> cert-manager-webhook-65ccc474d9-sjrkv
[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] spec/run: attempt 1 after 509ns ok: true
]]></system-out>
    </testcases>
    <testcases name="Cert Manager API Readiness Checks/verify webhook pod ready" time="7.535129ms" status="ok">
      <system-out><![CDATA[[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] using retry (exponential: true) [plugin default]
[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] using timeout of 5s [plugin default]
[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] kube.get: replaced name: $WEBHOOK_POD_NAME -> cert-manager-webhook-65ccc474d9-sjrkv
[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] kube.get: pods/cert-manager-webhook-65ccc474d9-sjrkv (ns: cert-manager)
[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] save.vars: WEBHOOK_POD_IP -> 10.244.0.5
[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] spec/run: attempt 1 after 798ns ok: true
]]></system-out>
    </testcases>
    <testcases name="Cert Manager API Readiness Checks/curl pod from test container" time="2.807446514s" status="ok">
      <system-out><![CDATA[[gdt] [Cert Manager API Readiness Checks/5:curl pod from test container] using timeout of 300s
[gdt] [Cert Manager API Readiness Checks/5:curl pod from test container] exec: replaced arg: http://$WEBHOOK_POD_IP:6080/healthz -> http://10.244.0.5:6080/healthz
[gdt] [Cert Manager API Readiness Checks/5:curl pod from test container] exec: kubectl [run chkk-cert-manager-api-check --image=curlimages/curl --rm -i --restart=Never --quiet --command -- curl -s http://10.244.0.5:6080/healthz]
[gdt] [Cert Manager API Readiness Checks/5:curl pod from test container] spec/run: single-shot (no retries) ok: true
]]></system-out>
    </testcases>
  </testsuite>
</testsuites>

or JSON output format:

$ gdt run ../../chkk-io/readiness-checks/guided/addons/cert-manager/api.readiness-after14.yaml -ojson
{
  "testsuites": [
    {
      "name": "api.readiness-after14.yaml",
      "time": "2.635655869s",
      "failures": 0,
      "errors": 0,
      "tests": 6,
      "timestamp": "2025-12-09T14:39:36.708906197-05:00",
      "properties": [
        {
          "name": "path",
          "value": "../../chkk-io/readiness-checks/guided/addons/cert-manager/api.readiness-after14.yaml"
        }
      ],
      "testcases": [
        {
          "name": "Cert Manager API Readiness Checks/ensure certificaterequest CRD installed",
          "time": "24.768068ms",
          "status": "ok",
          "assertions": 0,
          "system-out": {
            "Text": "[gdt] [Cert Manager API Readiness Checks/0:ensure certificaterequest CRD installed] using retry (exponential: true) [plugin default]\n[gdt] [Cert Manager API Readiness Checks/0:ensure certificaterequest CRD installed] using timeout of 5s [plugin default]\n[gdt] [Cert Manager API Readiness Checks/0:ensure certificaterequest CRD installed] kube.get: customresourcedefinitions/certificaterequests.cert-manager.io (non-namespaced resource)\n[gdt] [Cert Manager API Readiness Checks/0:ensure certificaterequest CRD installed] spec/run: attempt 1 after 831ns ok: true\n"
          }
        },
        {
          "name": "Cert Manager API Readiness Checks/ensure issuers CRD installed",
          "time": "35.025181ms",
          "status": "ok",
          "assertions": 0,
          "system-out": {
            "Text": "[gdt] [Cert Manager API Readiness Checks/1:ensure issuers CRD installed] using retry (exponential: true) [plugin default]\n[gdt] [Cert Manager API Readiness Checks/1:ensure issuers CRD installed] using timeout of 5s [plugin default]\n[gdt] [Cert Manager API Readiness Checks/1:ensure issuers CRD installed] kube.get: customresourcedefinitions/issuers.cert-manager.io (non-namespaced resource)\n[gdt] [Cert Manager API Readiness Checks/1:ensure issuers CRD installed] spec/run: attempt 1 after 1.202µs ok: true\n"
          }
        },
        {
          "name": "Cert Manager API Readiness Checks/cmctl check api",
          "time": "45.083687ms",
          "status": "ok",
          "assertions": 0,
          "system-out": {
            "Text": "[gdt] [Cert Manager API Readiness Checks/2:cmctl check api] using timeout of 10s [plugin default]\n[gdt] [Cert Manager API Readiness Checks/2:cmctl check api] exec: cmctl [check api]\n[gdt] [Cert Manager API Readiness Checks/2:cmctl check api] exec: stdout: The cert-manager API is ready\n[gdt] [Cert Manager API Readiness Checks/2:cmctl check api] spec/run: single-shot (no retries) ok: true\n"
          }
        },
        {
          "name": "Cert Manager API Readiness Checks/get webhook pod name",
          "time": "7.492367ms",
          "status": "ok",
          "assertions": 0,
          "system-out": {
            "Text": "[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] using retry (exponential: true) [plugin default]\n[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] using timeout of 5s [plugin default]\n[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] kube.get: pods (labels: app.kubernetes.io/component=webhook) (ns: cert-manager)\n[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] save.vars: WEBHOOK_POD_NAME -\u003e cert-manager-webhook-65ccc474d9-sjrkv\n[gdt] [Cert Manager API Readiness Checks/3:get webhook pod name] spec/run: attempt 1 after 685ns ok: true\n"
          }
        },
        {
          "name": "Cert Manager API Readiness Checks/verify webhook pod ready",
          "time": "10.682972ms",
          "status": "ok",
          "assertions": 0,
          "system-out": {
            "Text": "[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] using retry (exponential: true) [plugin default]\n[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] using timeout of 5s [plugin default]\n[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] kube.get: replaced name: $WEBHOOK_POD_NAME -\u003e cert-manager-webhook-65ccc474d9-sjrkv\n[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] kube.get: pods/cert-manager-webhook-65ccc474d9-sjrkv (ns: cert-manager)\n[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] save.vars: WEBHOOK_POD_IP -\u003e 10.244.0.5\n[gdt] [Cert Manager API Readiness Checks/4:verify webhook pod ready] spec/run: attempt 1 after 522ns ok: true\n"
          }
        },
        {
          "name": "Cert Manager API Readiness Checks/curl pod from test container",
          "time": "2.512603594s",
          "status": "ok",
          "assertions": 0,
          "system-out": {
            "Text": "[gdt] [Cert Manager API Readiness Checks/5:curl pod from test container] using timeout of 300s\n[gdt] [Cert Manager API Readiness Checks/5:curl pod from test container] exec: replaced arg: http://$WEBHOOK_POD_IP:6080/healthz -\u003e http://10.244.0.5:6080/healthz\n[gdt] [Cert Manager API Readiness Checks/5:curl pod from test container] exec: kubectl [run chkk-cert-manager-api-check --image=curlimages/curl --rm -i --restart=Never --quiet --command -- curl -s http://10.244.0.5:6080/healthz]\n[gdt] [Cert Manager API Readiness Checks/5:curl pod from test container] spec/run: single-shot (no retries) ok: true\n"
          }
        }
      ]
    }
  ]
}

Issue #69