Remove some/all functionality in tests/features directory

I don't believe the `tests/features` directory is being used at all. All tests have passed with the folder disabled.

I propose removing this directory altogether, or at a minimum removing unused code.

Start by inspecting the tests/features directory and checking whether anything in the repository references it. Run the test suite with that folder disabled, as described in the issue, and verify that tests still pass. Done means the unused directory or clearly unused code is removed without breaking the test suite.

Vom Indexierungsmodell aus dem Issue-Text verfasst.