Engine E2E/fuzz testing

[benthevining]

Scripted in Python.

• Get/set options, load/save state from config file
• Check that engine info prints correct version
• Try sending commands during search
• Try setting invalid option values, invalid option names

[benthevining]

Could also fuzz the EngineBase class by using a simple random mover subclass

[benthevining]

See https://github.com/official-stockfish/Stockfish/blob/master/tests/instrumented.py