Inventory rewrite

[RoyalMCPE]

This is still very early stages. Panics, item duplication and other bugs are almost guaranteed. You have been warned

This implementation is a complete mess right now and currently doesn't allow opening inventories. I already have ideas on cleanup and improving api, I mostly just wanted to resolve import cycles and compile errors first. If you're looking through this mess key places are world/inventory.go, world/tx.go, block/chest.go, world/world.go.

TODO

• Migrate Chest/Double Chest
• Migrate Barrel
• Migrate Brewing Stand
• Migrate Ender Chest
• Migrate Hopper
• Migrate Furnace/Blast Furnace/Smoker
• Save/Loading from disk
• Migrate Player
• Close inventory related issues
• Virtual inventories
• Event handlers
• Documentation

Goals

• Have inventories be managed by the world for; better data loading/unloading, general safety, and to align their design with the rest of the dragonfly.
• Set the ground works to emulate from in a future entity rewrite

Notes

• The current implementation uses a library I created here based on work from karl-zylinski. I haven't had time to benchmark it, but once I do and the implementation looks good I'll probably just copy pasta it into 'server/internal'.
• Like *player.Player it's not recommended to store a inventory.Inventory as it could be invalidated without warning. *world.InventoryHandle should be stored instead

Related Issues

• Proposal: Inventory Rework #984