Optimize Chunk Generation

[sylv256]

The chunk generation is currently based on Minecraft's implementation. However, it can and should optimized. (see Lithium)

[valoeghese]

The worldgen in chunk generation is probably the main bottleneck. At some point I might use JFR or something and profile the worldgen to see what i can optimise.
I might just remove any unnecessary caches as well to try speed things up

[sylv256]

what's FIFOCache for?

[valoeghese]

I can't remember what I used it for. It's a first-in-first-out cache

[valoeghese]

I have a different kind of cache for worldgen