[Sandbox] High-Explosive Shells Revision: Join the Testing!

Falathi: SPG have not been changed in this iteration and honestly can`t say if, and how they would be changed. @Zer0RNG The thing is that if we`re going to rebalance all ammo then we should include HE as well. 
As for HESH: they are a separate sort of ammunition and are not included in this iteration. It looks they won`t treated the way they are now - as just HE with better pen.