Consistency Issues with PDB & MMTF IO for structure 5EIL

[t0mdavid-m]

For the purpose of testing the added functionality in #425, I added the structure with the PDB ID 5EIL to the test data. While the tests for filter.py are passing as expected, the tests test_array_conversion() in test_pbd.py and test_mmtf.py are failing.

I am particularly worried about the test case in test_mmtf.py as the atom_name annotations seem to change when reading and writing a mmtf file (which is what is being tested):

Original AtomArray: ...'CE1', 'NE2', 'H', 'HA', 'HB2', 'HB3', 'HD1', 'HD2', 'HE1', 'N'...
After writing and reloading: ...'CE1', 'NE2', 'H', 'HA', 'HB2', 'HB3', 'HD2', 'HE1', 'HE2', 'N'...

The test in test_pdb.py fails because the following error is not raised:

if hybrid36 and (array1.res_id < 1).any():
            with pytest.raises(
                ValueError,
                match="Only positive integers can be converted "
                      "into hybrid-36 notation"
            ):
                pdb_file = pdb.PDBFile()
                pdb.set_structure(pdb_file, array1, hybrid36=hybrid36)