Missing Horse Armor and Triming Horse Armor.

Hello!  So, this is kinda embarrassing, but it would seem that Netherite Horse Armor doesn't exist.  Also, the ability to Trim Horse Armor seems to be missing as well.  Not sure why this is, but if you could fix this quickly it would be much obliged.  Thanks, and have a great day.  Rockatoa, Brickticks out!