Execute the Scenario-Tests in CI

[MichaelSimons]

The scenarios tests should be run as part of both the source-build and unified build CI legs. The tests should run with the SDK and runtimes produced by the build

[ViktorHofer]

I think it would make sense to hook the build and test of the scenario-tests repo onto the --test action in the build script. There's also the DotNetBuildTests property which might make sense to honor. cc @mmitche

[mmitche]

DotNetBuildTests is unrelated. It generally refers to repo level unit tests. I think scenario tests are somewhat different? I would still want to be able to run them against an official build, without having to build all tests in an official build.

Otherwise using --test sounds reasonable as a first approach. I think if we end up with executable unit tests in the VMR that may need to be re-visited.

[mthalman]

How do we want this to work in terms of building the tests and running the tests? The runtime repo allows for build/test to be one action or to only test w/o a build. Do we want similar behavior here? In that case, should there be a --test-no-build option added?

[ViktorHofer]

Yes, I think it makes sense to support --test-no-build / /p:TestNoBuild. I originally added that to runtime as the vstest msbuild integration had it as well.