ideally this should of never mattered, as it will only
be hit if you teleport out of an unloaded chunk...
But apparently some people are triggering this.
See #1223
Spigot had code that returned early in chunk add/remove methods.
This was causing our code added to set current chunks and counts to
be skipped over if the entity was default not persistent but made persistent.
This was the source of many issues
Fixes#1208
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.
