OnWorldLoaded dispatcher reset

[Erlandys]

There could be a way to reset OnWorldLoaded dispatcher, for some additional ingame functions. For example, if player is teleported to some other location, loading screen could be shown, VoxelWorld itself would not be recreated, but since invoker is moved to new location, loading screen should be shown until all VoxelWorld tasks are finished (spawners, meshers), but currently OnWorldLoaded dispatcher is fired only after first full load and in such case, such loading screens are possible only if Recreate function for VoxelWorld is called.