Improve parsing of VsTest.Console.exe results to stabilize end to end tests

[csoltenborn]

Currently, our end to end tests normalize the output produced by VsTest.Console.exe and then compares it to golden files. This approach has been rather unstable so far, since the output changes quite often (and might even be in a different language).

We should evaluate other options:

• check the output files produced by the tool - can they be used for verifying the desired behavior? Do they even provide enough information to verify correct test execution?
• otherwise, we should create a dedicated (and more maintainable) output parser