ASP.NET functional test projects not detected by convention

To match the [ASP.NET guidelines](https://github.com/aspnet/AspNetCore/wiki/Engineering-guidelines#assembly-naming) we'd need to update [this line](https://github.com/dotnet/arcade/blob/192cd9aec1f743f302c4e395bb33286bfe9dcc41/src/Microsoft.DotNet.CoreFxTesting/build/TestProject.props#L21) to include assemblies that end with `.FunctionalTests`.

I believe these should be categorized as unit tests and not integration tests because they're not typically not as heavy-weight as the integration test category implies. They can probably run during live testing. But that's just my opinion.

Another, somewhat related thing that KoreBuild did was run unit tests before these functional tests. The idea being that if a unit test failed, functional tests would probably fail too. We wanted to fail fast and the unit tests are typically a lot faster to run than the functionals.

cc @natemcmaster @ryanbrandenburg @rynowak