Feature-request: Enable subtracting polygons from graph

[rdnfn]

Description: For the policy use-case it would be great if we could subtract a given list of polygons from an existing GeoGraph via a subtraction function with a similar signature as below. By subtracting, I mean any polygon in the graph df has its intersection with the given list of polygons removed. The resulting graph may have fewer nodes than the original.

This would be helpful for building a feature that allows users to evaluate the impact of a land cover change (e.g. removing the given polygons from a habitat) on the habitat. Combining this function with ipyleaflet draw control and the GeoGraphTimeline, it would be relatively simple to allow the user to interactively draw polygons corresponding e.g. to planned infrastructure. Overall, this could be a very powerful feature for policy advisors.

def subtract_pgons_from_graph(graph: geograph.GeoGraph, polygons: List[shapely.Polygon]) -> geograph.GeoGraph:
    """Return graph resulting from subtracting polygons from given graph."""

Note: This feature may be out of scope for pre-report-submission.