Inventory Expansion

Huge behind the scenes update:
- Converted to multi-loader setup, so I can develop for forge and fabric at the same time.
- Added more compatibility with better nether, better end, and gardens of the dead
- Fixed flickering issue when changing the selected index. Especially noticeable on a server.
- Fixed flickering issue when using an item from a sack.
- Pick block now works on sacks, updating the selected index if no other item is in your inventory that it can fetch.
- Fixed various issues with inserting items into sacks/quivers/bundles when the item is the result of a crafting recipe.
- Fixed bug where the selected index would start at the wrong spot when changing it within a bundle.
- Added Container Item behavior API, which lets developers easily add more container items without having to create more mixins.
- Renamed \`sack\_type\_default\` and \`sack\_weight\_default\` to \`sack\_type\_rule\` and \`sack\_weight\_rule\`.
- Added \`sack\_type/none\` item tag, which prevents items from being inserted into sacks.