This simply provides the base API to create the objects. Further commits will come that adds
adds usage of this API to existing GameProfile based API's, as well as new API's.
In 1.12, Spigot improved their blockstate implementation to take a full
copy of the TE, this allows for a much better snapshot in that it will
actually retain all of the TE's state, it is a much more expensive
implementation. This is also implicated with their backwards compat
for inventories meaning that accessing of a snapshots inventory of a
placed block will actually access the inventory of the live TE, making
creation of a snapshot redundant if the only intent is to interact with
the TEs inventory.
Hoppers are a horrible hit, every attempt to transfer an ItemStack will
result in two TileEntity snapshots, with two hoppers and a double chest
ontop, I managed to log 380 cases per second where a snapshot would have been
taken in cases where the snapshot is redundant.