XpNoCooldown and combineXpOrbs refactor (#1149)

* - Fix xpNoCooldown to work as it did in 1.17-
- Remove XPcombine
- Use vanilla merge methods

* Remove debug code

* fix: rollback sort carpet.mixins.json

* rework: nerf xp cooldown absorption a little

* remove: combineXpOrbs
fix: xpCooldown

* revert renames

* fix newlines

* fix: wrong implementation for absorption

* add missing `private` keyword

* fix: player xp cooldown set wrongly

* fix: injection point to be within condition

src/main/resources/carpet.mixins.json

@@ -78,6 +78,7 @@
     "MinecraftServer_scarpetMixin",
     "PlayerListHeaderS2CPacketMixin",
     "ExperienceOrbEntityMixin",
+    "PlayerEntity_xpNoCooldownMixin",
     "PlayerActionC2SPacketMixin",
     "ServerPlayerEntityMixin",
     "PlayerManager_coreMixin",