[FFC] Production scaling from land change

[jucordero]

Model behaviour
This function changes food quantities in a Food Balance Sheet array element by scaling them relative to the change in a Land Data Array category quantities.

Expected parameters for this function include:

• Food Balance Sheet to scale
• Reference and target land data arrays
• List of categories to monitor
• List of items to scale
• List of items to use as padding, if the total quantity is expected to remain constant

Links to modelling document and future_food repository
This function is intended to perform a similar scaling to the one presented in the production_land_scale function of the Future Food Calculator model, which is being worked on #100

[jucordero]

The definition of the function should be added to the agrifoodpy.food.model module, and include the pipeline_node decorator to allow pipeline execution by providing datablock keys to the food balance sheet and land data arrays.

e.g.:

#agrifoodpy/food/model.py
@pipeline_node(["fbs", "land", "land_reference"])
def food_scaling_from_land(
    ...
    return scaled_fbs
)

from agrifoopy.pipeline import Pipeline
from agrifoodpy.food.model import food_scaling_from_land
fs = Pipeline()
...
fs.add_node(
    food_scaling_from_land,
    params={
        "fbs":"datablock_key_to_fbs",
        "land":"key_to_land",
        "land_reference":("baseline", "key_to_baseline_land")
        ...
    }
)