Add Cataclysm DBC compatibility guards

[MadMaxMangos]

Add Cataclysm DBC field guards to Eluna

Summary

• Add CATA-specific shared-field and spell-family selections across Eluna's MaNGOS hooks and methods.
• Keep every new CATA arm under ELUNA_MANGOS.
• Preserve CLASSIC, TBC, WOTLK, MISTS, and non-MaNGOS behavior.

Commits

• Base: 37d964e
• Head: 735b67ecafefdc76a1124a1cfbe1397bf6d9cd93
• Range: 2 commits, 8 files, 48 insertions.

Validation

• git diff --check passed.
• Three's shared-consumer preflight checked the CATA fields against the final server declarations while preserving the other expansion surfaces.
• Included in the MaNGOS Three RelWithDebInfo build and successful DBC/DB2/world boot gate.
• Independent scoped review: APPROVE, no findings. The reviewer confirmed the final CATA fields, mutually exclusive guards, unchanged expansion arms, preserved non-MaNGOS paths, and balanced preprocessing.

Delivery

Merge this companion branch before the MaNGOS Three server branch, then update the server gitlink to the permanent merged-master SHA.

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