Whenever a block is updated, ensure that an updated version of the relevant node is written to the save file. When a world is initialized on the server-side, all modified chunks are loaded from the save file and stored in memory, to be retrieved whenever the relevant node is to be added to the graph.

This is a temporary implementation, as it does not properly scale for larger worlds, where we may not want to store all modified chunks in RAM.

Note that while this implements loading save data, it only loads voxels. Entity locations, such as the player's location, are ignored.