Remove ammo from non-combat merchants

[chief-turkler]

Changes

Removed ammo stocks from most non-combat traders.
Also made some changes to availability of ammo in traders. Combat merchants are left unchanged, slavers get a small amount of small-caliber ammo because their occupation is basically aligned with violence and it'd make sense for them to sell some alongside other slavery gear.

Reasoning

• It doesn't make sense for people dealing in metals and fresh produce to stock autocannon shells.
• Combat Extended currently has a feature where if a weapon is found in a trader's inventory/in a quest reward/in a pod drop/etc. it will also have fitting ammo alongside it. If a merchant is selling a gun, it's already going to be selling ammo for that gun.
• Dedicated combat merchants already exist and it makes them a bit pointless if most traders can stock most ammo.

Alternatives

Current system:

• Breaks immersion.
• Kinda ruins the point of having seperate combat traders if bulk goods traders are equally as capable of stocking mortar shells.

Testing

Check tests you have performed:

• Compiles without warnings - Changes do not require a recompile
• Game runs without errors
• Playtested a colony (specify how long) - 10-20 minutes to make sure I haven't broken anything

[github-actions]

You can download the rebuilt assembly for this PR here: https://combatextended.lp-programming.com/CombatExtended-27128820749.zip

[chief-turkler]

This is probably a bit extra but trade tags for certain ammo types would be neat so that we can have slavers always stock non-lethal ammo like beanbags and whatnot.