Unlocking countryballs after a trade on confirm stage times out

[domino6658]

Describe the feature you'd like
Countryballs would be unlocked immediately after ConfirmView times out. This would be done by adding a on_timeout callback which unlocks the balls in both player's proposals and then cancels the trade in a way similar to using the Cancel button.

Additional context
Currently, if the trade has not finished 90 seconds after both players have locked their proposals, the ConfirmView will time out and the balls will remain locked until 15 minutes have passed since the beggining of the trade.

[flaree]

It was intentionally left to wait the 15 minutes incase there's any issues and to avoid potential race conditions

[domino6658]

to avoid potential race conditions

@flaree what do you mean by this? would you please mind elaborating a bit on why it was intentionally left to wait 15 minutes and if or if not it can be changed?