Improve AI strike targeting.

We were setting up all the correct *target* waypoints but the AI doesn't
use the target waypoints; they use the targets property of the ingress
waypoint. This meant that the flight plan looked correct in the UI and
was correct for players but the tasks were set up incorrectly for the AI
because building TGOs are aggravatingly multiple TGOs with the same name
in the implementation.

Mission targets now enumerate their own strike targets so that this
mistake is harder to make in the future.

This won't be perfect, the AI is still not able to parallelize tasks and
since buildings aren't groups they can only attack one structure at a
time, but they'll now at least switch to the next target after hitting
the first one.

As a bonus, stop bombing the dead buildings.

Fixes https://github.com/dcs-liberation/dcs_liberation/issues/235
Fixes https://github.com/dcs-liberation/dcs_liberation/issues/244

changelog.md

@@ -10,6 +10,7 @@ Saves from 2.5 are not compatible with 3.0.
 * **[Campaign AI]** Every 30 minutes the AI will plan a CAP, so players can customize their mission better.
 * **[Campaign AI]** AI now considers Ju-88s for CAS, strike, and DEAD missions.
 * **[Campaign AI]** Fix purchase of aircraft by priority (the faction's list was being used as the priority list rather than the game's).
+* **[Flight Planner]** AI strike flight plans now include the correct target actions for building groups.
 * **[UI]** Added new web based map UI. This is mostly functional but many of the old display options are a WIP. Revert to the old map with --old-map.
 * **[UI]** Campaigns generated for an older or newer version of the game will now be marked as incompatible. They can still be played, but bugs may be present.
 * **[UI]** DCS loadouts are now selectable in the loadout setup menu.