Add support for datapack custom loot tables to Dungeon chests

[BubblesIsEpic]

This simplifies the process of learning the ItemsXL loot tables which I have found to have minimal documentation and would save having to figure out the IXL loot tables until there is some form of tutorial

[Sataniel98]

But the process of learning how ItemsXL loot tables work is learning the command to create them is /ixl lt [name].

[BubblesIsEpic]

But using datapacks for loot tables allows more customisation with things such as enchant randomly and random damage on weapons