STRETCH GOAL: Implement one-to-many mapping for manure to nutrient analyses

[raarielgrace]

Describe the task
Right now, a manure can only be mapped to one nutrient analysis. In old NMP, you could apparently add an arbitrary number of nutrient analyses to a manure. In the calculate nutrient page, they could select one nutrient spec for part of the manure and a different one for another application.

Additional context

• Another potential solution would be to add a button to copy a manure's values, then assign these different manures their own nutrient analysis.