Fabric Shield Lib

Changes

• Split FabricShieldItem into FabricShieldItem & FabricBannerShieldItem
• Made FabricShieldBannerDecoratorRecipe use FabricShield interface instead of FabricShieldItem class
• Fixed incorrect license information in fabric.mod.json

Changes

• Finally added banner support! Special thanks to CringeStar
• Now using Fabric's event system instead of ShieldEvents.
• Custom shields are identified using an interface instead of inheritance.
• Mixins shouldn't conflict with other mods(ex. Requiem)
• Library was rewritten and simplified, less strange behavior should occur.

Should hopefully Fix #22 & Fix #16

Added enchantability to constructors

Reformatted a bunch of code