Function game::info::calculate_unedited_map

fn calculate_unedited_map(
    ctx: &mut EventCtx<'_>, 
    app: &App
) -> Option<Transition<App>>

If needed, makes sure the unedited_map is populated. Callers can then do app.primary.unedited_map.borrow().unwrap_or(&app.primary.map) if this returns None. If a transition is returned, that must be executed first.