Fixed C4 target inconsistencies with Fog of War and Husks

Closes #5566
This will leak information about whether the frozen actor is dead (`target.Actor == null`).
We may need to introduce an `IDemolishableInfo` that we can check against using only the ActorInfo.

This will be too big of a change to sneak in at the last minute, so this may have to stay broken for now, as it isn't a show-stopper.