this implementation is working, although incomplete:
- The shulker close sound should not be played until the end of the shulker closing animation, which takes approximately 1 second.
- An open shulker box has a different collision box than a closed one - it should be +0.5 in whichever direction the shulker is facing. (During the animation, the bounding box also dynamically changes size - you can see this in vanilla by shooting an arrow into the top of an open shulkerbox facing UP, and then closing it - the arrow will fall and collide with the lid multiple times.
However, resolving both of these issues requires significant internal changes which are beyond the scope of this PR.
