`is_subgroup()` modifications in `SpaceGroup` and `PointGroup`

[kaueltzen]

Summary

Resolves #3937 .

SpaceGroup

• enabled isomorphic group subgroup relationships, added test
• Constrained https://github.com/materialsproject/pymatgen/blob/02341828b94a001b4f3cbdae6b24eaeeb0df7d7d/src/pymatgen/symmetry/groups.py#L528 to non-klassengleiche group subgroup relationships so cases like assert SpaceGroup("Fm-3m").is_subgroup(SpaceGroup("Pm-3m")) pass, added test
• fixed bug introduced by me in #3859 (Apologies!) of wrong short Hermann Mauguin symbol computation for multiple trigonal groups
• modified point_group entries of symm_data.json to be possible symbol attributes of PointGroup (also see comment below)

PointGroup

• added crystal_system attribute to PointGroup
• enabled init from other settings than in database and from full symbol, added test
• added notes in docs that axes of PointGroup object may differ from given int_symbol in init / given space group symbol in from_space_group as currently only one setting per point group is available
• added crystallographic direction issue check for is_subgroup of PointGroup -> a NotImplementedError is now raised if the blickrichtungen / crystallographic directions of the crystal systems of the two groups differ

[kaueltzen]

Hey @shyuep @mkhorton @janosh this is ready to be reviewed.