Add Shared Pools to Biogas

[Shad0wlife]

Consider making the biogas mod target shared animal farm pools to support modded animal farms like industrialized low tier.

[jakobharder]

We haven't done that in the past because packed farms like that don't produce milk :)

Either way, animal farm pools can't be used because I have different targets depending on their production cycle (30s, 60s and 90s) to produce the same amount per minute for all.