Overhaul muzzle loaders

[kevingranade]

Summary

None

Purpose of change

I was reminded that muzzle-loader reload times were incredibly short (3s for blunderbusses, 6 - 12s for flintlocks), and when I took a look I noticed several other issues related to damage output and ammunition composition.

Describe the solution

Extend reload times to 30 seconds nominal, which is dropped as low as 15s with very high skills.
Adjust damage type of blunderbusses, it was still stab.
Adjust damage of muzzle loaded rounds based on the sqrt(J) standard (documented in the balance doc).
Added a lead shot blunderbuss round.
Removed silly nonmetallic options from the "scrap" blunderbuss round. (feel free to add this as a new, really terrible round if you like).
Obsoleted the "scrap blunderbuss slug" recipe as utterly nonsensical.

Describe alternatives you've considered

I considered unifying the blunderbuss and flintlock ammo types, but just thinking about working through the migrations that would require gave me a headache.
I want to revisit blunderbuss utility when I overhaul shot to be multi-projectile, I found some credible sources that indicate it does have an extreme amount of spread compared to regular shot.

Testing

Load the game, shoot stuff.