CaptureActor as Enter subclass & fixes 6658
Demolish as Enter subclass
RepairBuilding & RepairBridge as Enter subclasses
DonateSupplies as Enter subclass
Infiltrate as Enter subclass
Removed Enter(Actor self, Actor target, Activity inside) & made Enter abstract
Restricted terrain targeting to force-move enter transports
Added bridge hut repair tracking
Merge pull request #6662 from atlimit8/CaptureActor-Enter

 Enter subclasses & fix for 6658
Add an aspect ratio correction flag to VqaPlayerWidget.
Make the video cancel hotkey configurable.
Prevent mouse events from propagating through a video.
Fix the title of the TD missions panel.
Add support for mission groups.
Add support for briefing videos in the mission menu.
Upgrade TD missions for the new mission chooser.
Upgrade RA missions for the new mission chooser.
Add support for thirdparty missions.