Fix sg

[minhsueh]

Fix space group parsing:

1. Centralize the use of unicodeify_spacegroup from Pymatgen.
2. Fix htmlify_spacegroup.

Note: Testing is blocked until the corresponding Pymatgen PR is merged.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.13%. Comparing base (23efcfc) to head (af39197).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1501      +/-   ##
==========================================
- Coverage   85.14%   85.13%   -0.01%     
==========================================
  Files         230      230              
  Lines       18904    18896       -8     
==========================================
- Hits        16096    16088       -8     
  Misses       2808     2808              

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