Invariable Paintings

Features:

• Added a custom CIT logic for painting items. This uses its own resource-pack format, but is easier to setup than CIT-resewn, and yields better performances. CIT-resewn is still compatible, but no longer necessary.
• Painting items with an invalid variants now have a unique icon.
• Creative players can pick a painting's variant by holding Ctrl when picking.
• The loot function lock_variant_randomly was renamed to invarpaint:lock_variant_randomly. The old name is still functional, but will be removed in future releases.

Rebalance:

• Increased the emerald price of painting trades, and reduced the amount of trades before they expire.
• Shepherds now also require a blank canvas in their price. (Wandering traders are unaffected.)
• The "Recycling" preset no longer prevents the crafting of blank canvases.