Beans Backpacks

• Added Winged Backpacks
• Added Ender Backpacks (more info)
• Added elytra_items in Data-Pack's modify folder (more info)
• Renamed New Duds Advancement description to Equip a Dyed Backpack
• Many changes to Backpack Entities and Inventories

Some features aren't fully fleshed out yet, I started a discussion for this update to talk changes and features.

! ! ! BACKUP YOUR WORLDS ! ! !

Much of the code that stores items has changed in this version! I try to test as much as possible before releases but some issues slip past and I don't want your items to be lost because of it. Thank you for playing my mod in the early stages. If you find any issues leave them on github. ;)