Add two telemetry metrics to AIShell to get an idea of the usage

[daxian-dbw]

PR Summary

Add 2 telemetry metrics to AIShell:

1. SessionCount: tracking the number of sessions get started. It sends custom dimensions uuid, os, and standalone, so we will know the unique users, the platforms, and whether a session is standalone.
2. QueryCount: tracking the number of queries get asked. It sends custom dimensions uuid, agent-name, and remote, so we will now the distribution of the queries based on unique users, agents, and whether it's a remote query.

The telemetry can be opted out by setting the environment var AISHELL_TELEMETRY_OPTOUT to 1 or true.

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If we ever need to disable or reject telemetry ingestion from the AppInsights service side, we do one of the followings:

1. Set a daily limit on data ingestion with Daily cap
   • "Configure" -> "Usage and estimated cost" -> "Daily cap"
2. Reduce the percentage of telemetry ingested with Data sampling
   • "Configure" -> "Usage and estimated cost" -> "Data sampling"
3. Connection string rotation

None of them will cause issues on the client side.