Restrict animal slaughter by milk/wool threshold

[RobRoseKnows]

Problem description
I would like to restrict animal slaughter to those below a certain milk/wool threshold, so that I don't slaughter animals that are about to get sheared/milked.

Describe the solution
Would be nice to have a slider/text box for animals like there's a bonded/pregnant checkmark now.

Additional materials
I'd love to submit a PR for this if you don't have time to work on it, but I want to ensure it's the kind of feature you'd incorporate first.