previously, these were forced to extend BaseInventory because of the amount of crap in Inventory's interface.
This meant that these inventories had their own slots storage, which would be _mostly_ unused because these inventories aren't real inventories, but rather just delegates.
This lead to a variety of bugs in the past, such as certain API methods on BaseInventory not working correctly for DoubleChestInventory in particular.
Now, BaseInventory just implements the functional part of the inventory implementation, leaving the storage system up to the implementation.
A SimpleInventory class is provided with a simple SplFixedArray storage backing, which is used by most inventories.
EnderChestInventory and DoubleChestInventory now extend BaseInventory directly, and implement custom methods for dealing with their delegates.
now, EnderChestInventory is just a temporary window, much like anvil/enchanting windows. It provides a gateway to the player's PlayerEnderInventory.
This removes one of the remaining obstacles to disallowing null World in Position constructor.
this isn't practical to fully implement right now due to limitations
imposed by the legacy shitfest system we're using. To make stripped
dynamic, we would need to switch the IDs _and_ variant info dynamically,
and I have no idea what bizarre side effects that might have.
setRotation() is conditionally useless, but there's not much we can do about this right now; and exposing it like this is better than having plugins interacting with tiles.
this implementation is very rough due to having to hack around lots more MCPE bullshit, and currently doesn't allow dynamic coral types; but it's there. We'll clean this up after 1.13 migration is done.
