Dehardcoding "ItemStack.isOf" checks

[Leo40Git]

As of Minecraft 1.16, the following items are special-cased using ItemStack.isOf calls (AKA ItemStack.getItem() == SPECIFIC_ITEM_INSTANCE):

• Bows
• Crossbows
• Shields
• Elytras

This essentially means adding a new variant of any of the above items is impossible without mixins.

I suggest that QSL should dehardcode these checks, to allow for custom bows/crossbows/shields/etc.

I'm not sure if this should be an API necessarily, AFAIK the main thing holding back custom bows/etc is the hardcoded checks.

[OroArmor]

I already have libraries waiting for qsl to pass rfc for these