Playground for standalone dashboard

[JamesNK]

Suggested #1556 (comment)

I think the best way to test this out is to have an Aspire host project launch aspire dashboard as usual, but it is configured to not know about resource service. Another app in the host project sends the dashboard telemetry

[kvenkatrajan]

Addressed with : dotnet/aspire-samples#135
@JamesNK please confirm and close.

[DamianEdwards]

Samples != playground. I think this issue is about adding it to playground in this repo.

[kvenkatrajan]

Sorry my bad - makes sense.

[JamesNK]

This isn't urgent.