To get the old behavior, you now need to refer to the internal keywords
(like "bird_medium" or "quadruped_small") rather than the old friendly
names (like "duck" or "pig"), as the latter generate single species now.
Is also able to refactor some of the uglier code and introduces a
framework that (suitably extended) could be useful in removing
boilerplate elsewhere.
fix(overflow): Stops including block updates that fail (since chunks
don't exist on the client) in `TerrainUpdates` (which would trigger
meshing of those nonexistent chunks). Furthermore, removes
remeshing of chunks with block updates if those chunks don't have all their
neighbours (since those wouldn't be meshed in the first place).
