Improved SourceTests, again

Removed GetXListTest, because it was obsolete.

Fixed:
- If run locally, BlockCharcacterTest and LicenseTest failed files in 'build' folder (changed Utils.accept)
- BlockCharcacterTest also failed on strings.xml and UiTestUtils, fixed Test to read files with utf8

Improved:
- if we only check .java files, lets only check files in /src folders.
- added folder LegoNXTBTTests to some Tests.
- error messages, (Path instead of FileName) and one was just plain wrong
- all directory arrays are defined in the Utils class, to reuse and only have one place to change things (for example if a subteam adds a directory)
- BlockCharcacterTest, check for other unwanted Unicode characters

The overall time to run the tests was reduced from 3.3 seconds to 1.9 seconds.