add some more damage functionality

[pingu7867]

Here're the things I mean by this, which would be good to have in PAC. Though there is abuse potential in some of them (though there is abuse potential in other existing parts, so I guess as always it's a trusting people's goodwill thing, and there are countermeasures that we could conceive)

-Hits positioning for parts. Could be a part which would contain children parts (effects, sounds, maybe decals or fading models (I know what could be the potential problem of not restricting them through time. rapid-firing models which could have them either flash in and out of existence in a zeptosecond or not show at all, or stay forever becoming cancerous clutter)) deployed on hits of hitscan nature (I assume projectile weapons fundamentally work someway else. Let's not worry about these at first). Most weapons have spread, and for achieving impact effects hitpos won't cut it because with the discrepancy between the center of aiming and where the bullets spread out, there might be impact effects on a target when a bullet missed that target, and there might be an impact effect not on the target when a bullet hits off-center.

-Hitscan damage instead of only projectiles. I quote Jarmmo from discord:
Jarmmo - Today at 1:07 PM
"Yeah i've seen alot of people want a hitscan part(edited)
Might want to suggest that on github"

-Providing something to replace your damage with any of the source damage types.

-Temporary parts on killed targets. I'm thinking of the TF2 energy weapons' disintegration kill effects. PAC having a way to detect targets killed would be a great feature so this kind of thing could be achievable.