Add GameService service.

[ndouglas]

The issue I'm having currently is organizing the different steps that need to take place in order for the game to actually start. I've had this working, broken it, fixed it, broken it, etc. Consequences of a growing design that's becoming increasingly abstract.

My GameState should house a GameService that manages these details. Probably a state machine whose transitions encompass the various actions that need to occur in order to start a game.

I need to:

• Wipe out the game data directory (see Create GameFileService. #30)
• Create a new game data directory (see Create GameFileService. #30)
• Create a new seed string, or accept one provided as input (see Create Seed String Service. #31)
• Create a new chunk world -- one world per game data directory at this time, so it can have a pre-determined identifier, derived from the seed string (see Create ChunkWorldCreatorService. #32)
• Within the chunk world, create a new chunk plane, save it, set it as the world's primary plane (see Create a ChunkPlaneCreatorService. #33, Create a ChunkWorldProcessorService. #36, Create ChunkWorldProcessor that acts on the ChunkPlaneCreatorService. #48).
• Within the primary plane, generate the chunk seeds, chunks, etc (see Create a ChunkPlaneProcessorService. #34, Create a ChunkPlaneProcessor that generates chunks. #37).
• Collect the closed, empty chunks and assign a central chunk to be a startable chunk (see Create a ChunkPlaneProcessor that tags a chunk as startable. #38).
• Construct the startable chunk (see Create a ChunkPlaneProcessor or ChunkPlaneProcessors that assigns initial variables to the chunks. #39).
• Collect the closed, empty chunks and use a WFC algorithm to assign biomes to the chunks (see Create Biome type. #29, Create a ChunkPlaneProcessorService. #34).
• Collect the closed, empty chunks and use a processor to assign transitions to other chunks to specified coordinates (see Create a ChunkPlaneProcessor that assigns transition points between adjacent chunks. #41).
• Collect the closed, empty chunks and use more processors to assign initial variables to the chunks (see Create a ChunkPlaneProcessor or ChunkPlaneProcessors that assigns initial variables to the chunks. #39).
• Collect the fully initialized-but-empty chunks and create maps in each of them (see Create a ChunkProcessor that builds a map within a chunk. #40).
• Collect the mapped chunks and populate them (see Create a ChunkProcessorService that processes created chunks. #42).
• Create the player.