Catch IllegalStateExceptions in BattleSimulation #8
Description
In #7 MCTS was implemented, but sometimes throws IllegalStateException if we run into a state that shouldn't occur.
We haven't experienced any of these yet, but it would probably be better to catch these in BattleSimulation so that the game doesn't crash.
However, if this happens we need to decide if we want the AI to make no move or do a random move so the game doesn't get stuck.