[MTP] IncludeTestAssembly default to true

[stan-sz]

In MTP (MSTest) the IncludeTestAssembly defaults to false. The ask is to make it default to true.

Code coverage of a test assembly has one practical meaning: in a PR, once presented to the reviewer that certain lines are covered, is an indication that the whole build+test+collect+visualize pipeline works.

[Youssef1313]

I personally do agree that IncludeTestAssembly is a better default.

In past, there was an ask for coverlet coverlet-coverage/coverlet#618 which I do agree with.

[Youssef1313]

@fhnaseer We will need to update the documentation as well.

[fhnaseer]

Test projects will be included by default in the coverage report from version 18.3.x onwards. Default behavior is now same as vstest.console.exe test.dll /EnableCodeCoverage.

[fhnaseer]

This change has been reverted due to dotnet test failing on linux. dotnet/sdk#52029