Improve pipeline

[renzo-baasdam]

Working on #379.

• Convert container to Linux
• Sonar complains about the Java version
  Cannot recreate warning.
• Build seems to fail due to not be able to load a dll
  Cannot recreate warning.
• Build claims to succeeded while all tests fail
  Fixed by separating a multi line command into 3 separate steps.
• Insight in tests is lacking (for inspiration see Buildalyzer)
  Seems to kindof work despite exceeding allowed size
  Test report summary is too big - setting 'listTests' to 'failed'

[Corniel]

I added a task: convert (back) to Linux. This might include running the netstandard2.0 unit test targets as .NET 4.8 instead over 3.1 core.

[Corniel]

LGTM! Thanks for effort.