Explosion falloff buff

[Safairette]

Changes

• Buffed explosion scaling to fall off more slowly and raised the lowest damage from 2 to 1/3 of the original damage.
• Changed minimum pen to 1/3 of base.

Reasoning

• Small explosives are punished too greatly by harsh falloff, losing a large chunk of their damage even on direct hits.
  • Related internal chat link: https://discord.com/channels/278818534069501953/310869202892488705/1303463301187108967
• Base game explosions don't get affected by falloff, making the harsh scaling of CE explosions jarring in comparison.

Alternatives

• Switch to linear scaling completely.
• Exist with sub-2 radius explosives being incredibly inconsistent due to impact cell variation.

Testing

Check tests you have performed:

• Compiles without warnings
• Game runs without errors
• Playtested a colony (specify how long)

[github-actions]

You can download the rebuilt assembly for this PR here: https://combatextended.lp-programming.com/CombatExtended-12458336636.zip

[N7Huntsman]

There was a long discussion regarding similar changes to the falloff suggested by #3093 that we ultimately decided against, and I'm inclined to stick with that for similar reasons.

Additionally, it seems to me that changing the minimum from a flat 2 to 1/3 of the base damage is likely to cut both ways--it's a reduction to any blast under 6 damage (and a very marginal improvement at best to any bigger "small explosions"), but stands to more significantly buff larger blasts.

[Safairette]

And I'm of the opinion that some form of change is very much needed. The current state of explosions, especially the smaller ones like 40mm grenades and all HEAT varieties is bordering on unacceptable. The center of the explosion being inconsistent on direct hits, as well as how harsh the falloff penalties are, reduce the intended damage on those explosions by a very significant margin. I'm willing to talk more about it, but something in the current explosion mechanics needs to change.