Add an option for default start type.

Changing this completely breaks OCA/Aircraft missions, but if the player
doesn't care about those this can reduce airfield congestion. The UI
warns about this.

This also makes the AI start type selectable in the flight UI.

Fixes https://github.com/Khopa/dcs_liberation/issues/387
Fixes https://github.com/Khopa/dcs_liberation/issues/729

game/settings.py

@@ -19,11 +19,12 @@ class Settings:
     supercarrier: bool = False
     generate_marks: bool = True
     manpads: bool = True
-    cold_start: bool = False  # Legacy parameter do not use
     version: Optional[str] = None
     player_income_multiplier: float = 1.0
     enemy_income_multiplier: float = 1.0
 
+    default_start_type: str = "Cold"
+
     # Campaign management
     automate_runway_repair: bool = False
     automate_front_line_reinforcements: bool = False
@@ -36,7 +37,6 @@ class Settings:
     perf_artillery: bool = True
     perf_moving_units: bool = True
     perf_infantry: bool = True
-    perf_ai_parking_start: bool = True
     perf_destroyed_units: bool = True
 
     # Performance culling