Add test helpers

[oerc0122]

Description of work

• Add test_helpers
  • Add paths test helper
  • Add compare_mdt to compare MDANSE trajectories.
  • Add get_deep_atr to extract attributes from nested objects.
• Refactor test_converter, test_editor and the Analysis folders to use new routines as well as pytest.

Fixes
Fixes #676

To test
Standard tests.

[MBartkowiakSTFC]

Interestingly, on my computer I got two failing tests.

This was with rdkit-2024.3.3 and upgrading to rdkit-2024.9.5 solved the problem.

I don't think that we need to do enforce a specific version of rdkit. But maybe later we should investigate test_rdkit.py and decide if it really is useful.

For the record, the error was:

Tests/UnitTests/molecules/test_rdkit.py .EE.                                                                        [100%]

========================================================= ERRORS ==========================================================
______________________________________________ ERROR at setup of test_rdkit _______________________________________________

    @pytest.fixture()
    def mol_from_rdkit():
>       mol = MolFromPDBFile(fname)
E       Boost.Python.ArgumentError: Python argument types in
E           rdkit.Chem.rdmolfiles.MolFromPDBFile(PosixPath)
E       did not match C++ signature:
E           MolFromPDBFile(char const* molFileName, bool sanitize=True, bool removeHs=True, unsigned int flavor=0, bool proximityBonding=True)

Tests/UnitTests/molecules/test_rdkit.py:21: ArgumentError
____________________________________________ ERROR at setup of test_splitting _____________________________________________

    @pytest.fixture()
    def mol_from_rdkit():
>       mol = MolFromPDBFile(fname)
E       Boost.Python.ArgumentError: Python argument types in
E           rdkit.Chem.rdmolfiles.MolFromPDBFile(PosixPath)
E       did not match C++ signature:
E           MolFromPDBFile(char const* molFileName, bool sanitize=True, bool removeHs=True, unsigned int flavor=0, bool proximityBonding=True)

Tests/UnitTests/molecules/test_rdkit.py:21: ArgumentError