Missing options for tie_breaking in QuantEcon/GameTheory

There are three options for tie_breaking in QuantEcon/GameTheory: "smallest", "random", and "False". False isn't really an option for tie_breaking as it returns all alternatives which are tied. (It doesn't "break" the tie.) "Random" is a tie breaker somewhat compatible with classical game theory. "Smallest" isn't: It relies on information not meant to be available to players: The arbitrary way, game theorists list strategies in the normal form of a game.

There should be additional options, compatible with the information reasonably assumed to be available to players in a "learning" game. One of them I would call "conservative": If no other strategy leads to higher "utility" don't change your strategy. (This would be an easy one to implement, I guess.)

So please, add this option.

Start by locating the QuantEcon/GameTheory implementation of the tie_breaking options and review how "smallest", "random", and False are handled. Define the requested "conservative" behavior from the issue text, then identify the relevant existing tests or examples and verify that the new option preserves the current behaviors.