Dan's massive refactor

Squashing 8 commits by DanAlbert:

- Track theater in ControlPoint.
Simplifies finding the owning theater of a control point. Not used yet.

- Clean some cruft out of FlightPlanBuilder.
- Clean up silly some exception handling.
- Move FlightPlan instantiation into the builder.
I'm working on moving the builder to be owned by the Flight, which will simplify callers that need to create (or recreate) flight plans for a flight.

- Simplify IBuilder constructor.
We have access to the theater via the flight's departure airbase now.

- Move FlightPlan creation into Flight.
For now this is just a callsite cleanup. Later, this will make it easier
to separate unscheduled and scheduled flights into different classes without complicating the layout/scheduling.

- Remove superfluous constructors.
- Remove unused Package field.

game/campaignloader/mizcampaignloader.py

@@ -107,9 +107,8 @@ class MizCampaignLoader:
         if self.mission.country(self.RED_COUNTRY.name) is None:
             self.mission.coalition["red"].add_country(self.RED_COUNTRY)
 
-    @staticmethod
-    def control_point_from_airport(airport: Airport) -> ControlPoint:
-        cp = Airfield(airport, starts_blue=airport.is_blue())
+    def control_point_from_airport(self, airport: Airport) -> ControlPoint:
+        cp = Airfield(airport, self.theater, starts_blue=airport.is_blue())
 
         # Use the unlimited aircraft option to determine if an airfield should
         # be owned by the player when the campaign is "inverted".
@@ -252,20 +251,26 @@ class MizCampaignLoader:
         for blue in (False, True):
             for group in self.off_map_spawns(blue):
                 control_point = OffMapSpawn(
-                    str(group.name), group.position, starts_blue=blue
+                    str(group.name), group.position, self.theater, starts_blue=blue
                 )
                 control_point.captured_invert = group.late_activation
                 control_points[control_point.id] = control_point
             for ship in self.carriers(blue):
-                control_point = Carrier(ship.name, ship.position, starts_blue=blue)
+                control_point = Carrier(
+                    ship.name, ship.position, self.theater, starts_blue=blue
+                )
                 control_point.captured_invert = ship.late_activation
                 control_points[control_point.id] = control_point
             for ship in self.lhas(blue):
-                control_point = Lha(ship.name, ship.position, starts_blue=blue)
+                control_point = Lha(
+                    ship.name, ship.position, self.theater, starts_blue=blue
+                )
                 control_point.captured_invert = ship.late_activation
                 control_points[control_point.id] = control_point
             for fob in self.fobs(blue):
-                control_point = Fob(str(fob.name), fob.position, starts_blue=blue)
+                control_point = Fob(
+                    str(fob.name), fob.position, self.theater, starts_blue=blue
+                )
                 control_point.captured_invert = fob.late_activation
                 control_points[control_point.id] = control_point