Customizable Player Models

Added /cpm scaling debug <player> command, lists all of the scaling settings
Updated Spanish translations (#761)
25w18a port

Rewrote the pehkui scaling system
Fixed ConcurrentModificationException errors while loading models
Removed remove flight speed attribute scaler (didn't actually work)
Fixed 0 sized cubes still drawing triangles
Fixed paste client delete confirm popup missing OK button text
Marked the bukkit plugin as incompatible with forge/neo/fabric