Openapoc: End Game does not trigger on destruction of dimension gates

[FilmBoy84]

The end game video and prompt does not trigger on leaving the dimension gate generators with a successful mission.

Instead the player is able to go back to the city and cause chaos (see today's quickmind stream)

Maybe freeplay should be an option longer term, but for now, the game should end as per OG

On mission successful, as soon as return to cityscape display victory prompt, then run video, then return to main menu (or if we add it, prompt to free-play)

[Quickmind01]

The game should end when you click OK on the Debriefing screen once the mission is complete. OG doesn't even allow you to go back to the Alien Dimension before the final score is shown and the movie plays.