Decentralize ``small_animal`` and ``fish`` factions

[Karol1223]

Summary

None

Purpose of change

As I outlined in #75829 I wanted to decentralize small_animal to allow for better hunting simulation of small animals. This aims to achieve that.

Describe the solution

Factions done:

• [x] Mammals
• [ ] Birds + Bat
• [ ] Reptiles
• [ ] Frogs
• [ ] Fish

Describe alternatives you've considered

Testing

Additional context