Fix Vanilla Bug, use official Hytale API for ActiveChunkUnloader with configurable offset and implement chunkunloader whitelist

[Xytronix]

Summary

Fixes a bug where paused players' chunks unload when standing still on pause screen for 7,5 seconds.

I implemented a configurable spawn exclusion list and rewrote ActiveChunkUnloader to use official patched methods.

Key changes:

• Fixed vanilla ChunkUnloadingSystem to skip paused players (null transformComponent)
• Added spawn chunk protection for both vanilla and Refixes systems
• Implemented persistent chunk loader service
• Added /refixes chunkloader command, supports add, remove and list

Type of change

• Bug fix (non-breaking)
• New feature (non-breaking)

Implementation details

• MixinChunkUnloadingSystem: Overwrote collectTrackers() to use ChunkTracker.shouldBeVisible() instead of getChunkVisibility(), properly handling paused players
• Added spawn protection injection to prevent spawn chunks from unloading
• MixinPlayerChunkTrackerSystems: Sets minLoadedChunksRadius on player add
• MixinPlayerViewRadius: Updates radius when view distance changes dynamically
• ActiveChunkUnloader: Reduced in size and uses now official vanilla API
• ChunkLoaderService: Managing persistent chunk loaders
• ChunkLoaderCommand: Command with support for coordinates, current position and label
• ChunkLoaderWorldListener: Restores chunk loaders on world load
• Permissions: hytale.command.refixes.chunkloader.{add,remove,list}

Checklist

• Code compiles successfully
• Pull request does not contain unrelated changes
• Changes follow this project's code style
• Changes are tested or will be tested after submission