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.

changelog.md

@@ -213,6 +213,7 @@ BAI/ANTISHIP/DEAD/STRIKE/BARCAP/CAS/OCA/AIR-ASSAULT (main) missions
 * **[Data]** Added support for the ARA Veinticinco de Mayo.
 * **[Data]** Changed display name of the AI-only F-15E Strike Eagle for clarity.
 * **[Flight Planning]** Improved IP selection for targets that are near the center of a threat zone.
+* **[Flight Planning]** Moved CAS ingress point off the front line so that the AI begins their target search earlier.
 * **[Flight Planning]** Loadouts and aircraft properties can now be set per-flight member. Warning: AI flights should not use mixed loadouts.
 * **[Flight Planning]** Laser codes that are pre-assigned to weapons at mission start can now be chosen from a list in the loadout UI. This does not affect the aircraft's TGP, just the weapons. Currently only implemented for the F-15E S4+ and F-16C.
 * **[Mission Generation]** Configured target and initial points for F-15E S4+.