add biome change per player

[yannicklamprecht]

resolves #9889

TODO:

• Implement and call event
• finish implementing BiomesSnapshot
• add a handle to Chunk
• test api with plugin
• test compatibility with plugins using PlayerChunkLoadEvent
• reduce diff
• add paper comments

[Owen1212055]

We have a more generalized idea for something like this via our registry api, prolly better to wait.

Would allow us to make any registry modifiable.
Nvm, wrong thing.

[Machine-Maker]

I'm thinking it would still be useful to get the biomes being sent by vanilla. Right now, the event is only dealing with any overrides. Implementing this might also be way nicer if this event was implemented on the server side. So the creation of BiomeSnapshots could be done in a lazy fashion to avoid creating snapshots for everything just to call the event.