1.21.2 and 1.21.3 port

Technical

• Bosses now have Bossbars, because NMR does no longer supports Bossbars

• Do to Mojangs changes on Potions; old (pre 1.21.2) Beverages bought by Mesa Barkeeper are now Nameless, including the ones they sell. If you want to fix the Barkeeper, you can spawn a new one with /function kattersstructures:mobs/mesa_barkeeper