Idea: Allow users to override character selection per match in a bracket

[Wolfy76700]

Users should be allowed to override the character selection in a bracket on a match-per-match basis, with StartGG imports being able to set said override whenever they happen.

NB: The idea of "overriding" said selection would probably be easier for a manual end user as it would allow them to set the player's main in the player list as it works now, but then pick and choose specific matches where another character was selected, but the program itself may require some extra intelligence to determine upon import which character a player has picked the most