this makes it easier to spot errors.
there's nothing we can do about the metadata values, but IDs can be quite easily constified.
there might be some weird artifacts where constants are aliased (e.g. appleenchanted) , but this is inarguably better than baking numeric IDs.
we don't usually add VanillaItems entries for blocks since they already exist in VanillaBlocks, but air has a special use case specifically as an itemstack, so we make an exception for this case.
this doesn't implement the server-side logic for the "stickiness" (slowdown) because we don't have the system needed for it yet.
It also doesn't have parity with vanilla on the damage.
