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