Should fix#1280
Citizens hijacks entity map, and im guessing under the right conditions
the result might actually be null during entity creation
Pre the cache patch, the id is looked up on save, so it was fine.
Now, if its null and the save ID is requested, we will try to look
it up again and cache it if found.
Closes#1197
While this really undoes a lot of the desired performance gains avoiding chunk lookups,
we sadly have to accept this because we are seeing lots of bugs with entities.
This enables us a fast reference to the entities current chunk instead
of having to look it up by hashmap lookups.
We also store counts by type to further enable other performance optimizations in later patches.
To teleport an entity between dimensions, the server makes a copy
and puts the copy in the new location, and marks the old one dead.
If this method got called for the same world in the same tick,
the entity would not have been removed from the UUID map, and the
world readd would fail.
This can be triggered even with a plugin if the entity is teleported
twice in the same tick, from world A to B, then back from B to A.
The re-add to A will fail to add the entity to the world. It will
actually be there, but it will not be visible on the client until
the server is restarted to re-try the add to world process again.
This bug was unlikely to be seen by many due to the double teleport
requirement, but plugins (such as my own) use this method to
trigger a "reload" of the entity on the client.
