Fix stalemate logic to end 0 att plane vs. transport fights.

[asvitkine]

Change Summary & Additional Notes

Without this, we would trigger the 10K rounds limit in AI simulation when the battle ends up with a strat bomber (that has no attack or defense) faced off against a transport and/or subs, and neither would be able to damage the other.

Added a unit test. Also renames a couple of existing tests for clarity.

Fixes: #10936

Note: This problem does not exist in 2.5 (tested).

Release Note

[panther2]

@asvitkine
Why can't a strat bomber hit a transport? That's quite unusual.
That must be a speciality of the specific map?

[TheDog-GH]

Its from Global 40 House Rules with Canada

Above is not my map, however I have tried something similar for one of mine.

Here is an xml extract of the bomber

    <!-- BomberA0C5 -->
    <attachment name="unitAttachment" attachTo="bomberA0C5" javaClass="games.strategy.triplea.attachments.UnitAttachment" type="unitType">
      <option name="movement" value="6"/>
      <option name="isAir" value="true"/>
      <option name="attack" value="0"/>
      <option name="defense" value="0"/>
      <option name="isStrategicBomber" value="true"/>
      <option name="isInfrastructure" value="true"/>
      <option name="bombingMaxDieSides" value="6"/>
      <option name="canBeGivenByTerritoryTo" value="British"/>
      <option name="airAttack" value="0"/>
      <option name="canAirBattle" value="true"/>
      <option name="destroyedWhenCapturedBy" value="Germans:Russians:Americans:British:UK_Pacific:French:Italians:Japanese:Chinese:ANZAC:French:Dutch"/>
    </attachment>

[asvitkine]

Right, sorry in this case the strat bomber has no att/def, only used to damage factories, etc.