Several minor cleanups/fixes

[tal5]

Changes

• Makes WardenChangesAngerLevelScriptEvent's determination registration properly use registerOptionalDetermination to return false for invalid input.
• Added a default implementation for BlockHelper#getMapColor using Spigot's new BlockData#getMapColor.
• Removed EntityHelper#getEntity(World, UUID) in favor of Spigot's Bukkit#getEntity(UUID).
• Added a default implementation for EntityHelper#getPlayersThatSee using Spigot's new Entity#getTrackedBy.
• EntityTag#getEntityForID now uses Bukkit#getEntity.
• Replaced redundant early return usage in EntityBoatType#setPropertyValue.
• Removed the redundant attacker.getEquipment().getItemInMainHand() != null from EntityHelperImpl(1.20)#getDamageTo, as getItemInMainHand isn't nullable.
• PlayerHelperImpl(1.20)#refreshPlayer now uses ServerPlayer#createCommonSpawnInfo instead of manually creating the spawn info.
• BiomeNMSImpl(1.20)#getSpawnableEntities now uses the new CraftEntityType#minecraftToBukkit instead of the existing hacky conversion.
• Moved the DisguisePacketHandlers to after the EntityMetadataPacketHandlers, to avoid stuff like the invisible command overriding disguised entity's visibility.
• DisguisePacketHandlers#processTeleportPacket now uses DenizenNetworkManagerImpl#copyPacket instead of manually creating a new packet and copying values over (which also means relevant reflection constants were removed).
• Removed some old commented out ClientboundAddPlayerPacket handling code.
• Fixed PlayerTag.skin_model breaking on 1.17 because Spigot's player profile API didn't exist back then, and uses a MultiVersionHelper because Java doesn't like it when enums that don't exist are referenced.

Additions

• MultiVersionHelper1_18 - used by PlayerTag.skin_model, because that API didn't exist before 1.18 and it has an enum.