Add build annotations for test failures

[pepone]

Github provides an API to add annotations to checks, we can use this to display the actual test failures, NUnit can provide the location of the test failures.

So when a new PR breaks a test you will get an annotation similar to what you get with some GitHub actions https://github.com/marketplace/actions/lint-action

There is Nunit report action here https://github.com/marketplace/actions/nunit-reporter

Maybe we can use that and is just a matter of installing it with our workflow https://github.com/zeroc-ice/icerpc-csharp/tree/main/.github/workflows

[pepone]

I will reopen if MirageNet/nunit-reporter#22 gets fixed