Add a real CAS ingress point.

Putting the ingress point directly on one end of the FLOT means that AI
flights won't start searching and engaging targets until they reach that
point. If the front line has advanced toward the flight's departure
airfield, it might overfly targets on its way to the IP.

Instead, place an IP for CAS the same way we place any other IP. The AI
will fly to that and start searching from there.

This also:

* Removes the midpoint waypoint, since it didn't serve any real purpose
* Names the FLOT boundary waypoints for what they actually are

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/2231.

game/ato/packagewaypoints.py

@@ -9,7 +9,7 @@ from game.ato.flightplans.waypointbuilder import WaypointBuilder
 from game.flightplan import JoinZoneGeometry
 from game.flightplan.ipsolver import IpSolver
 from game.flightplan.refuelzonegeometry import RefuelZoneGeometry
-from game.persistence.paths import liberation_user_dir
+from game.persistence.paths import waypoint_debug_directory
 from game.utils import dcs_to_shapely_point
 
 if TYPE_CHECKING:
@@ -30,8 +30,6 @@ class PackageWaypoints:
     ) -> PackageWaypoints:
         origin = package.departure_closest_to_target()
 
-        waypoint_debug_directory = liberation_user_dir() / "Debug/Waypoints"
-
         # Start by picking the best IP for the attack.
         ip_solver = IpSolver(
             dcs_to_shapely_point(origin.position),
@@ -40,7 +38,7 @@ class PackageWaypoints:
             coalition.opponent.threat_zone.all,
         )
         ip_solver.set_debug_properties(
-            waypoint_debug_directory / "IP", coalition.game.theater.terrain
+            waypoint_debug_directory() / "IP", coalition.game.theater.terrain
         )
         ingress_point_shapely = ip_solver.solve()
         if dump_debug_info: