Port java integration tests to pytest.

Some notes:
* These tests rely on a variety of fixtures
* The previous maven-wrapper checks were checking for the version of maven installed by looking at the checked-in wrapper script. I dropped this behavior.
* I replaced a lot of test queries that queried for a (subset of) source archive files with the source_archive fixture. In particular, tests that excluded properties files from being listed in the expected output now include them.
   It's much faster to generate this list via the fixture instead of using CodeQL for it.

Author: criemen