Implement 12.0.0 transmog system

[Olcadoom]

Implements outfit-based transmogrification (12.0.1+) across server code and DB.

Key changes:

• Add SQL migration: character_transmog_outfits table for persisting outfit presets.
• CollectionMgr: populate AccountTransmogUpdate.NewAppearances so the client Items tab is filled.
• Player: add ACTION_BUTTON_TRANSMOG_OUTFIT action type, expose equipment sets getter, set HasTransmog/HasIllusion update fields when updating visible item slots, and fully implement _LoadTransmogOutfits to initialize default/viewed outfits, populate 30-slot layout, and restore saved outfits into update fields.
• Handlers: force transmog-related game rule/vars for client UI in AuthHandler/CharacterHandler; implement transmogrification handlers in TransmogrificationHandler (HandleTransmogOutfitUpdateSlots, HandleTransmogOutfitNew, HandleTransmogOutfitUpdateInfo, HandleClearNewAppearance) to validate NPC, apply/reset appearances & illusions, charge cost, update UpdateFields and _equipmentSets, persist new outfits, and send confirmations.
• Packets: add serialization for TransmogOutfitSlot, reading/writing outfit packets and response packets.
• Spells: implement EffectEquipTransmogOutfit (effect 347) for quick-applying outfits via action bar spell cast.

Purpose: bring server support for retail-style transmogrification outfits (creation, editing, applying, persistence, and client UI compatibility) so clients can use the outfit UI and the server can store and apply outfit presets.

Changes proposed:

• Add character_transmog_outfits SQL migration table for persisting outfit slot data per character
• Implement _LoadTransmogOutfits in Player to initialize default Outfit 1, restore saved outfits into UpdateFields with full 30-slot layout (armor + weapon sub-slots), and populate situations
• Add ACTION_BUTTON_TRANSMOG_OUTFIT (0x90) enum and validation so outfit icons persist on the action bar across relogs
• Expose GetEquipmentSets() public getter on Player for spell effect access
• Set HasTransmog/HasIllusion update fields in SetVisibleItemSlot for correct client rendering
• Populate AccountTransmogUpdate.NewAppearances in CollectionMgr so the client's Items tab displays collected appearances
• Force transmog-related GameRules and MirrorVars in AuthHandler/CharacterHandler to enable the client outfit UI
• Implement HandleTransmogOutfitUpdateSlots: validates NPC, maps outfit slots to equipment slots, applies/resets appearances and illusions with cost checks, updates UpdateFields and _equipmentSets for DB persistence, sends confirmation packet and visual effect
• Implement HandleTransmogOutfitNew: creates new outfit presets with current gear appearances, initializes situations, persists to _equipmentSets
• Implement HandleTransmogOutfitUpdateInfo: handles outfit rename/icon changes
• Implement HandleClearNewAppearance: handles clearing the "new" flag on collected appearances
• Add packet serialization for TransmogOutfitSlot, TransmogOutfitUpdateSlots, TransmogOutfitSlotsUpdated, TransmogOutfitNew, TransmogOutfitNewEntryAdded, TransmogOutfitUpdateInfo, TransmogOutfitInfoUpdated, and ClearNewAppearance
• Register all new opcodes (CMSG + SMSG) in Opcodes.cpp and handler declarations in WorldSession.h
• Implement EffectEquipTransmogOutfit spell effect handler (effect 347) for quick-applying outfits via action bar spell cast, reading outfit SetID from m_misc.Raw.Data[1]

Issues addressed:

Closes # N/A - new feature implementation

Tests performed:

• Builds successfully with Visual Studio (no compile errors or warnings)
• Tested in-game: created multiple outfit presets via transmog NPC UI
• Verified outfit quick-apply via action bar spell cast (spell 1247613) switches between outfits correctly
• Confirmed outfit icons persist on action bar after relog (action type 144 fix)
• Verified appearances, secondary shoulders, and illusions apply and reset correctly
• Confirmed outfits persist across server restarts via DB save/load
• Validated against retail sniff data for packet structure correctness

Known issues and TODO list:

• Weapon sub-slots (SlotOption 3-11) are skipped during outfit apply - only primary weapon appearances (SlotOption 1/2) are processed
• Outfit deletion handler not yet implemented