Restructure the chunk meshes to reduce memory usage

[IntegratedQuantum]

FaceData currently makes up ~30% of the total memory usage (at render distance 24)

This is really not necessary. The face data is stored twice: Once in a large array, and once in multiple arraylists for types/neighbors/lod neighbors.
I think the optimal behavior would be to only keep these arraylists locally on the stack when creating the mesh. Then they should be merged/added into the big list right away, instead of collecting them in bulk at the end. This will require some more copying, but I think overall it should be better than keeping so many lists of duplicate data.