[EMF] Entity Model Features

RC-2

• added a random entity display to the config screen
• fixed null pointer exception with model overrides
• fixed ravager jaw having the wrong OptiFine part name
• fixed is_on_shoulder animation variable
• fixed wolf_collar.jem loading
• fixed an accidental limitation where a vanilla part unknown to the OptiFine part name map would be targeted by animations intended for custom parts (in FA this was parrot heads and witch hats)
• fixed a crash with unknown models building illegal paths
• fixed an issue with parts with empty ids using "this" animation key
• fixed book models
• fixed chest & shulker model mixups
• fixed animations not being read from models with parts with duplicate ids (fixed several of Creepermax123's packs)