feat: Implement diffing algorithm for MapTemplates

[Restioson]

This PR implements a very coarse diffing algorithm for map templates. It is intended to be used with NucleoidMC/plasmid#293 as such:

The functionality offered is therefore pretty much the bare minimum to support that use case.

        if (newTemplate.diff(oldTemplate).needsRegeneration()) {
            gameSpace.getWorlds().regenerate(world, new TemplateChunkGenerator(server, newTemplate), newTemplate.getBounds().union(oldTemplate.getBounds()));
        }

The diffing algorithm uses the BLAKE3 hash function internally to compare MapChunks.

It takes around 100ms to hash a map that takes 400ms to load (based on siege:jungle). Therefore, the first hot reload of the map would take 100ms (hash old map) + 400ms (load new map) + 100ms (hash new map) + (negligible comparison) = 600ms. On second reload, the old map doesn't need to be hashed, so it would be 500ms.

[Restioson]

This could probably be optimised somewhat by keeping the hash on the entire template rather than each MapChunk, but this would somewhat weaken encapsulation. I don't really have the bandwidth to change it and it's a minor optimisation for a use-case that isn't very performance-critical (reloading).