Make FMP work with WorldEdit

Instead of replacing all tiles on chunk load, this substitutes a delegate map into the chunk that swaps all incoming tile entities if needed. This allows it to work with WorldEdit and pretty much anything else, as the swap is part of the integrated system of loading tiles. The delegate map helps by allowing other map swaps to happen with other mods, increasing compatibility, and if MC ever makes a more efficient chunk map the efficiency will carry over to this map as well.
If this is actually needed, make swapMulti return a map containing the tiles that aren't swapped, and use reference comparison