Add complete protocol 769 support for Minecraft 1.21.4:
- Version constants: Add 769 to supported versions, MC_1_21_4_Version constant,
and version string mappings (including 1.21.3 -> 768 compatibility)
- Item palette: 10 new items (Resin series + Eyeblossom), generated ItemPalette1214
- Entity palette: Remove CreakingTransient (149 entities, down from 150)
- Block palette: 10 new blocks with correct blockstate ID ranges from server data
- Packet palette: Serverbound packet ID reshuffling - PickItem split into
PickItemFromBlock/PickItemFromEntity, new PlayerLoaded packet inserted after
PlayerInput, subsequent IDs shifted accordingly. Clientbound unchanged.
- PlayerLoaded: Send empty PlayerLoaded packet after JoinGame processing (>= 1.21.4)
- EntityMetadata/DataComponents: Reuse 1.20.6 palettes (unchanged registries)
- Update all version guard checks from MC_1_21_2 to MC_1_21_4
Made-with: Cursor
