Add missing baby & scaled mob models & textures

Add all baby mobs models and textures with certain considerations:
1. Baby mobs should have unique names when applicable
   Axolotl -> larva, bee -> brood, fox -> kit, goat -> kid, horse -> foal, llama -> cria, polar bear -> cub, squid -> paralarva, and turtle -> hatchling.
2. Baby mobs should consider real-life counterparts in their design.
   Kittens have blue eyes. Kits have blue eyes and gray or light gray fur. Broods are white. Paralarva are semi-transparent.
3. Non-animal mobs should be included. (Piglins, zombies, villagers, and variants).
4. Armor should have models and textures for applicable babies (zombies and variants).

Also add models & textures for scaled mobs (slimes, magma cubes, giants, and salmon).