Allow setting logo for app registrations

[gabbsmo]

Related command
az ad app create

Is your feature request related to a problem? Please describe.
Currently it is very unintuitive to add a logo image to a app registration.

Describe the solution you'd like
--logo "@path/to/logo.png"

Describe alternatives you've considered
Using the (Power)shell's HTTP client because az rest does not seem to work with images.

$graphJwt = az account get-access-token --resource-type ms-graph | ConvertFrom-Json -Depth 100
$headers = @{
    "Authorization" = "Bearer $($graphJwt.accessToken)"
    "Content-Type" = "image/png"
}
$bytes = [System.IO.File]::ReadAllBytes($logo)
Invoke-RestMethod -Uri "https://graph.microsoft.com/v1.0/applications/$($app.id)/logo" -Method PUT -Body $bytes -Headers $headers

[yonzhan]

Thank you for opening this issue, we will look into it.

[microsoft-github-policy-service]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @josephkwchan, @jennyhunter-msft.