Accessories Fabric 1.0.0 Beta 19 for 1.21

Major bug fixes for serialization issues and more.

Fixes:

Fix issues with exponentially increased fortune and looting amounts due when having accessories equipped
Fix possible crash with SlotAttributes containing invalid characters when saved
Prevent issues with duplicate Unique slots being able to be registered
Prevent crash when trying to remove modifier from no existing container
Fix issues with serializing render options leading to crashing or not saving data
Fix missing packet handler for holder data syncing
Fix missing slot info for when the slot amount is zero within the tooltip

Accessories