Change squadrons to operate out of a single base.

https://github.com/dcs-liberation/dcs_liberation/issues/1145

Currently this is fixed at the start of the campaign. The squadron
locations are defined by the campaign file.

Follow up work:

* Track aircraft ownership per-squadron rather than per-airbase.
* UI for relocating squadrons.
* Ferry missions for squadrons that are relocating.
* Auto-relocation (probably only for retreat handling).

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1138

qt_ui/main.py

@@ -233,10 +233,12 @@ def create_game(
     # way.
     inject_custom_payloads(Path(persistency.base_path()))
     campaign = Campaign.from_file(campaign_path)
+    theater = campaign.load_theater()
     generator = GameGenerator(
         FACTIONS[blue],
         FACTIONS[red],
-        campaign.load_theater(),
+        theater,
+        campaign.load_air_wing_config(theater),
         Settings(
             supercarrier=supercarrier,
             automate_runway_repair=auto_procurement,