Adding secondary part tracking hashmap

This should help identify when parts are double-added, and if they are
identical or different parts.

In the future, simply migrating to this "parts map" is probably
advisable.
Adding isInvalid checks, on the off chance this fixes race conditions
Removing world-registry checks - these are not valid cases

These will always hit during a same-frame remove-and-add, but
remove-and-add is a valid scenario due to villagers. (Because villagers
chunk-thrash on the server when their chunk is unloading.)