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