Add MSTestV4 Support

[SeMuell]

This PR introduces support for the latest MSTest version (4.0) to fix the file not found issue in #424.

Since the MSTestV2 package was also compatible with MSTestV3, I added another test project to have proper testing.

However, maybe there is a better, future-proof way for the implementation I haven't found yet in comparison to the naive approach, I'll keep digging.

[SeMuell]

Having a loosely coupled dependency like FluentAssertions to 'Microsoft.VisualStudio.TestTools.UnitTesting.AssertFailedException' with reflection would also work here. Doing this the direct dependency on the TestFramework could be removed and may be more future proof (maybe reasonable doing the same for the other projects). What do you think?

[mlautin]

Hey, please review and finish this PR. This prevents upgrade to the latest MSTest.SDK.

[codecov-commenter]

Codecov Report

:white_check_mark: All modified and coverable lines are covered by tests. :white_check_mark: Project coverage is 73.79%. Comparing base (4006980) to head (1f9054d). :warning: Report is 15 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #426      +/-   ##
==========================================
- Coverage   74.84%   73.79%   -1.06%     
==========================================
  Files         257      259       +2     
  Lines       17221    16387     -834     
  Branches     1575     1336     -239     
==========================================
- Hits        12889    12092     -797     
- Misses       3876     3878       +2     
+ Partials      456      417      -39     

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[alexanderlinne]

@SeMuell, I unfortunately was missing a setting to require sign-off on web-based commits. So you'd have to add a sign-off on the last commit manually. Also, please update your branch with main and make sure the formatting is correct. Then I'll be able to merge and release a new version

[SeMuell]

Unfortunately, I am currently on vacation without access to a laptop. However, I'll try to manage it in the next two days.