Iron Chests: Restocked Barrel Fix

This datapack solves the issue of missing mineable/pickaxe tags for barrels made of various materials (iron, gold, diamond, copper, obsidian, and netherite) from the Iron Chests: Restocked mod. Without this tag, the mining time for such barrels was unrealistically long, and the barrels didn't drop as items after being broken.

After applying the fix and adding the correct mineable/pickaxe tag, the behavior of the barrels completely matches their chest counterparts from the same mod - they can be mined with a pickaxe and drop as items after being broken.