Port: Clean up test/ directory

[willieyz]

• The test/ directory has been cleaned up in mlkem-native: Clean up test/ directory mlkem-native#1345,
  same restructuring should be applied to mldsa-native for consistency.

Acceptance criteria:

• All configuration files as well as config.yml have been moved into test/configs.
• All test source files (except acvp_mlkem.c perhaps) are moved to test/src.
• All ACVP source and data (acvp_mlkem.c, acvp_client.py, .acvp_data) are moved to test/acvp/.
• All benchmarking files should be moved to test/bench/*.

Each item above will be addressed in a separate pull request.

[mkannwischer]

Completed by #843, #844, #845, #846