Initial work on the My Town Simulation

[sholloway]

This PR introduces:

• The ability to have coroutines run before the simulation starts.
• The Python 3.10 match statement.
• TOML files setting the canvas size.
• The rendering of the town and streets.
• The navigation mesh and A* based street navigator.
• The definition of layers moved to the TOML files.
• Red markers for every 10th grid line.
• Added a background to the stats HUD.
• Task for generating agents.