The End Update

Known issues:

• The wavy beacon effect from the Quantum Gateway doesn't seem to be achievable yet in 1.21.10
• Armor trimmed with Spectral Debris, Spectral Clusters, Pure Gravitite don't show trim overlays in their item sprites.
• The Shadow Altar's model should work like a spawner, in that you can see the backface of its textures from the inside of the block.
• The animation for using a Wooden Cone to get ice cream on a cow works, but plays nothing for Mooshrooms.
• TNT seems to have silk touch when destroying End Mire/End Murk.