Firearms expansion.

Isn't it odd how firearms never really malfunction or show any wear and tear? Or how all bullets are equal when it comes to quality and manufacturing? Or how the self-taught player character can turn out perfect quality reloads and sound suppressors using scrounged bits of trash?

This aims to fix all of that.

new system of firearm malfunctions, misfires, and failures which can require maintenance
firearms can take damage and be repaired using a calibrated tool kit
4 new gun mods
2 new tools
*many* new recipes
*many* new ammunition types
*many* bug fixes

fixes https://github.com/CleverRaven/Cataclysm-DDA/issues/6162