Iron Backpacks

Version 1.12 - 3.0.3:

Additions
- Added the ability to color backpacks
    - Shapelessly craft with dye, craft with water bucket to remove color
- Added the "Everlasting Upgrade"
    - It makes backpacks never despawn
- Added ability to remove upgrades
    - Backpack + shears in an anvil
- [Internal] Added the code base for the ability to equip backpacks
    - Disabled though, as it hasn't been tested enough and rendering isn't working yet
- {Internal] Added a new Blacklist to the API

Changes
- Specializations are now visually different (backpack clasp color)
- Slightly changed preexisting bag colors as well

Bug Fixes
- Fixed dupe bug when opening a backpack and tossing it away simultaneously.
- Fixed odd interactions with inventory sorting mods
- Fixed null backpack appearing as an ingredient when crafting higher tier ones