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

game/squadrons/operatingbases.py

@@ -0,0 +1,33 @@
+from __future__ import annotations
+
+import dataclasses
+from dataclasses import dataclass
+
+from game.dcs.aircrafttype import AircraftType
+
+
+@dataclass(frozen=True)
+class OperatingBases:
+    shore: bool
+    carrier: bool
+    lha: bool
+
+    @classmethod
+    def default_for_aircraft(cls, aircraft: AircraftType) -> OperatingBases:
+        if aircraft.dcs_unit_type.helicopter:
+            # Helicopters operate from anywhere by default.
+            return OperatingBases(shore=True, carrier=True, lha=True)
+        if aircraft.lha_capable:
+            # Marine aircraft operate from LHAs and the shore by default.
+            return OperatingBases(shore=True, carrier=False, lha=True)
+        if aircraft.carrier_capable:
+            # Carrier aircraft operate from carriers by default.
+            return OperatingBases(shore=False, carrier=True, lha=False)
+        # And the rest are only capable of shore operation.
+        return OperatingBases(shore=True, carrier=False, lha=False)
+
+    @classmethod
+    def from_yaml(cls, aircraft: AircraftType, data: dict[str, bool]) -> OperatingBases:
+        return dataclasses.replace(
+            OperatingBases.default_for_aircraft(aircraft), **data
+        )