Emulate block and item display entities in 1.19.4->1.19.3

[FlorianMichael]

This PR adds very basic handling for block and item displays.

Item displays:

(Implemented by setting the item as head armor on the invisible armor stand)

Block displays:

(Implemented by spawning a falling block and attaching it as passenger onto the armor stand to prevent position/rotation tracking)

Supersedes #538

[kennytv]

I don't actually see the falling block when summoning any block display (/summon block_display ~ ~2 ~ {transformation:{left_rotation:[12f,0f,0f,0f],right_rotation:[30f,0f,0f,0f],scale:[2f,1f,1f],translation:[0f,0f,0f]},block_state:{Name:acacia_log}} and joined with 1.16.5)

[FlorianMichael]

It should work now

whoops

[kennytv]

Works when spawned in next to you, but not when you join the server with one present or go in and out of range