Use the actual Country type instead of the name.

We want other pieces of country information (in particular the short
names). This cleans up a lot of code anyway.

As an added bonus, this now catches squadrons that used invalid names
which would previously be passed through to pydcs and... then I don't
know what would happen.

game/missiongenerator/visualsgenerator.py

@@ -99,7 +99,7 @@ class VisualsGenerator:
                             break
 
                         self.mission.static_group(
-                            self.mission.country(self.game.red.country_name),
+                            self.game.red.faction.country,
                             "",
                             _type=v,
                             position=pos,