Add settings UI for auto-ato behavior.

https://github.com/dcs-liberation/dcs_liberation/issues/276
https://github.com/dcs-liberation/dcs_liberation/issues/315

game/settings.py

@@ -1,10 +1,19 @@
 from dataclasses import dataclass, field
 from datetime import timedelta
+from enum import Enum, unique
 from typing import Dict, Optional
 
 from dcs.forcedoptions import ForcedOptions
 
 
+@unique
+class AutoAtoBehavior(Enum):
+    Disabled = "Disabled"
+    Never = "Never assign player pilots"
+    Default = "No preference"
+    Prefer = "Prefer player pilots"
+
+
 @dataclass
 class Settings:
 
@@ -37,6 +46,8 @@ class Settings:
     disable_legacy_aewc: bool = False
     generate_dark_kneeboard: bool = False
     invulnerable_player_pilots: bool = True
+    auto_ato_behavior: AutoAtoBehavior = AutoAtoBehavior.Default
+    auto_ato_player_missions_asap: bool = False
 
     # Performance oriented
     perf_red_alert_state: bool = True