Tweak automatic munition selection for low-ammo-count Autocannons

[Sleet01]

QA testing revealed that some units with single bins of AC10 and AC5 ammo would get Precision Autocannon munitions loaded, despite this significantly decreasing their mission endurance.

The issue was caused by a couple things:

1. Precision and Armor-Piercing munitions were not listed in the category "AMMO_REDUCING_MUNITIONS", so reducing the weight of the category would not reduce the weights of these munitions.
2. Standard munitions might not be selected as the primary ammo when two or more munitions tie for highest weight, so even if 1 is fixed, Standard munitions might not be selected.

Testing fixes for 1 and 2 revealed an opportunity to extend the Caseless ammo selection code for AC/20s to specific AC/10 and AC/5 situations as well.

Testing:

• Tested on MHQ campaign submitted by reporter of original bug (Thanks @Thom293 !)
• Ran all 3 projects' unit tests

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 28.98%. Comparing base (a55a508) to head (a4b3e17).
Report is 24 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #5860      +/-   ##
============================================
- Coverage     28.99%   28.98%   -0.02%     
+ Complexity    13930    13908      -22     
============================================
  Files          2512     2512              
  Lines        267289   267254      -35     
  Branches      47837    47787      -50     
============================================
- Hits          77510    77467      -43     
- Misses       185829   185830       +1     
- Partials       3950     3957       +7     

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[NickAragua]

Let's reduce copy-pasta a little bit.

[Sleet01]

Roping in @IllianiCBT as they are some fresher eyes on the project, and have not worked on this code before.

Do you mind taking a look at my proposed code, and @NickAragua 's suggested fix?

[IllianiCBT]

I know @Algebro7 is implementing some of the new Aero errata, but I don't know if they're doing the anti-ground errata. Tagging them here so that they're aware of this TODO (in case there is any cross-over).

[Sleet01]

Side note: anyone working on this will also need to touch the other MM, MML, and MHQ ammo validation code - it's not a small lift.

[IllianiCBT]

Do you mind taking a look at my proposed code, and @NickAragua 's suggested fix?

So I took a look, but I really don't feel qualified to make a decision given the substantially more experience you both have over me.

[Sleet01]

Do you mind taking a look at my proposed code, and @NickAragua 's suggested fix?

So I took a look, but I really don't feel qualified to make a decision given the substantially more experience you both have over me.

Alright, thanks for giving it a look-over.