Fixed missed initialization of unit data on load.

We'd only load unit data if a name lookup was done and missed it on a
type lookup. Ideally we wouldn't need to do a type lookup here until the
ground unit templates are reworked we still do.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/1299

game/dcs/groundunittype.py

@@ -45,6 +45,8 @@ class GroundUnitType(UnitType[VehicleType]):
 
     @classmethod
     def for_dcs_type(cls, dcs_unit_type: Type[VehicleType]) -> Iterator[GroundUnitType]:
+        if not cls._loaded:
+            cls._load_all()
         yield from cls._by_unit_type[dcs_unit_type]
 
     @staticmethod