* [xharness] Don't generate into the same directory/files for macOS Modern and macOS Full.
This meant that we were overwriting some generated files, which meant that we
were executing the Modern set of tests instead of the Full set of tests for at
least some configurations.
* Add a few ignored tests to the System.Configuration test now that we actually run it.
The change is a pre step to fix https://github.com/xamarin/xamarin-macios/issues/6162
We are removing the not longer child directory bcl-test/BCLTests since
there is not longer any reason for it to exist. The changes make sure
that the tests work as expected in the new directory.
Next step, move all the test apps to their own directory.
Rolf Bjarne Kvinge
Manuel de la Pena