FAIRmat-NFDI / nomad-simulations / 21392718281

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Restructure Single Symmetry into Global and Local Symmetry (#304)

Restructure symmetry into global and local components

Split the monolithic `ModelSymmetry` concept into `GlobalSymmetry` and `LocalSymmetry` 
subsections to properly distinguish between system-wide and per-particle symmetry properties, 
which transform under different conditions.

Architecture changes:
- Introduce `GlobalSymmetry` base class for system-wide symmetry specification
- Rename `CrystalSymmetry` to `GlobalCrystalSymmetry` extending `GlobalSymmetry`
- Change `ModelSystem.symmetry` from repeating to single subsection
- Create `LocalSymmetry` base class with `equivalent_atoms` for per-particle symmetry
- Create `LocalCrystalSymmetry` specialization with crystallographic quantities
- Add `LocalSymmetry` subsection to `Representation` (each representation has its own)
- This polymorphic design enables future extensions (magnetic, molecular symmetries)

Enhanced Bravais lattice specification:
- Split `bravais_lattice` string into two searchable `MEnum` quantities:
  - `lattice_type`: crystal family (a-triclinic, m-monoclinic, o-orthorhombic, etc.)
  - `lattice_centering`: centering type (P-primitive, I-body centred, F-face centred, etc.)
- Add `bravais_lattice` property for backward compatibility
- Fix Pearson notation parsing for multi-character family codes (2D/1D lattices)

Space group disambiguation:
- Add `hall_number` quantity (integers 1-530) for unique space group identification
- Different space groups can share the same international number but have different settings

Symmetry analysis fields from spglib:
- Add `analysis_origin_shift`: origin shift from standardized to input origin (3-element vector)
- Add `analysis_transformation_matrix`: transformation from input to standardized lattice (3x3)
- Add `site_symmetries`: crystallographic point group symbols for each atomic site

Wyckoff position improvements:
- Move `wyckoff_letters` from `Representation` to `LocalCrysta... (continued)

209 of 223 new or added lines in 4 files covered. (93.72%)

7346 of 8861 relevant lines covered (82.9%)

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