Armor trims for happy ghast, dogs, horse

We should be able to apply armor trims to dog armor, horse armor, and the happy ghast harness. This feature would allow players to personalize their dog armor, horse armor, and even the new happy ghast harness. There are other ideas people have for dog and horse armor that are quite good. For happy ghast there is a lot of space on the sides of the harness that could be utilized for trim customization.