Add an interface for Reinforcement Learning.
Implement a simple HTTP server to start games, receive the gamestate and pass commands to the simulation.
This is mainly intended for training reinforcement learning agents in 0 AD. As such, a python client and a small example are included.
This option can be enabled using the -rl-interface flag.
Patch by: irishninja
Reviewed By: wraitii, Itms
Fixes #5548
Differential Revision: https://code.wildfiregames.com/D2199