Clean up front line code.

The routes do not need be be recreated each time we create a
`FrontLine`. The front lines follow the convoy routes, which are static.
Add the convoy route data to the `ControlPoint` the way we do for
shipping lanes and have `FrontLine` load the data from there.

game/operation/operation.py

@@ -3,7 +3,7 @@ from __future__ import annotations
 import logging
 import os
 from pathlib import Path
-from typing import Iterable, List, Optional, Set, TYPE_CHECKING
+from typing import Iterable, List, Set, TYPE_CHECKING
 
 from dcs import Mission
 from dcs.action import DoScript, DoScriptFile
@@ -94,7 +94,7 @@ class Operation:
         )
         return Conflict(
             cls.game.theater,
-            FrontLine(player_cp, enemy_cp, cls.game.theater),
+            FrontLine(player_cp, enemy_cp),
             cls.game.player_name,
             cls.game.enemy_name,
             cls.game.player_country,