UndefinedOperationError for game.player.{actions,infosets} on non-tree

[rahulsavani]

closes issue #696

[rahulsavani]

In fixing this, I noticed that a bunch of functions on Game that only work for trees currently do not raise an UndefinedOperationError.

@tturcoy: Do we think that UndefinedOperationError should be raised by all of the following Game operations when called on a "non-tree"?

nodes, set_chance_probs, append_move, append_infoset, insert_move, insert_infoset, copy_tree, move_tree, delete_parent, delete_tree, add_action, delete_action, leave_infoset, set_infoset, reveal, sort_infosets.

If so, I can add an issue and add these errors and corresponding tests.

[tturocy]

I would say yes, please add a similar check to nodes as part of this PR.

For the others, they will all inherently fail because there'll be a game mismatch error because the parameter(s) of the functions won't belong to the game. So the check would largely be redundant - and at the end of the day the error that's raised now is also correct.

[tturocy]

Per comment - add this check to nodes as well please. Other functions looks like they're fine.

[rahulsavani]

Per comment - add this check to nodes as well please. Other functions looks like they're fine.

I added for nodes but also for sort_infosets (agree w.r.t. to all other functions that I mentioned: these will all raise other errors already that are correct too).