Graph: Allow dungeon to graph and graph to dungeon

[vantreeseba]

What it does

Set up a system where a graph (given the correct graph structure and data), can be given to the generator for some kind of generation to occur with (i.e. "prefab room placements with doors").

Also allow output from a generated dungeon on which region detection or other analysis has been done.

Implementation:

• Ensure region detection is working well enough to get regions.
• Think about region data structure, and what it should know.
• Store regions in a graph node, connect edges with door tiles on region to region edges.