Any full status chunk that was requested for any status less than full
would hold onto their entire nbt tree and every variable in that function.
This was due to use of a lambda that persists on the Chunk object
until that chunk reaches FULL status.
With introduction of no tick, we greatly increased the number of non
full chunks so this was really starting to hurt.
We further improve it by making a copy of the nbt tag with only the memory
it needs, so that we dont have to hold a copy to the entire compound.
Aikar