[MCM-1771] [Add-On issue] Invisibile Icon on Trimmable Custom Armor

Summary:

Trimmable armor is not possible in addon because it cannot recognized icon with namespaced texture. (`namespace:abyssalite_helmet` doesnt work but `abyssalite_helmet` works)

Impact:

Player got disappointed and complained it doesnt support trim. This reduce our review and impact our sales as those player will rate our content low stars.

Retro steps:

Create simple armor item
Add trim component
Set icon with texture with namespace in it (e.g texture: re_of:abyssalite_helmet)
Trim the armor

Observed result:

Icon will disappeared after get trims

Expected result:

Icon appears

Screenshots/Videos attached: Yes

Notes:

Currently its possible to implement custom trimmable armors as in version format version 1.20.70. The trimmed custom armor will have its icon automatically being trimmed too, but theres a issue in the code side.

Texture that set in `minecraft:icon` should be match with the item identifier WITHOUT namespace, for example:

item identifier: namespace:custom_armor

"minecraft:icon": {
 "textures": {
  "default": "namespace:custom_armor"
 }
}

with item_texture.json defined as:

"namespace:custom_armor": {
 "textures": "textures/items/custom_armor"
}

This will result invisible icon when item getting trimmed.

However the current way to make it works only through removing namespace from item_texture.json and minecraft:icon, which is:

item identifier: namespace:custom_armor

"minecraft:icon": {
 "textures": {
  "default": "custom_armor"
 }
}

with item_texture.json defined as:

"custom_armor": {
 "textures": "textures/items/custom_armor"
}

This will result in the custom armor icon getting trimmed too.

But this solution is not available for Marketplace Addons project because we need to set namespace on the item_texture.json.