Allow completed Mission maps to unlock other maps in the Mission selector. #41
Description
Practically this could mean missions in the mission selector being grayed out or missing in the mission list, until its parent mission triggers its visibility through a victory, with the state of completion being stored perhaps in something like the settings.yaml.
With the tutorial series in mind it might be advantageous to have the progression presented by having the next steps grayed out, showing the player the content of the 'course' however for the campaign it'd be more exciting having no idea of how far the player has progressed by rendering the next steps invisible.
Depending on how it's implemented it may run into the issue of how OpenRA updates its settings, more specifically regarding maps, as currently the map pool is updated only after restarting the client.
*Relevant OpenRA PR: OpenRA/OpenRA#15020