Add networkx's `from_biadjacency_matrix` and `biadjacency_matrix`

[michaelweinold]

What is the expected enhancement?

In NetworkX, I can create a graph based on a bipartite adjacency matrix using the from_biadjacency_matrix function. Rustwork currently has no such functionality. Similarly, I cannot create a biadjacency matrix from a graph.

This would be tremendously helpful in applications where I have information on edges between two set of graph nodes stored in a non-sqaure matrix (=biadjacency matrix).

[IvanIsCoding]

I think the challenge for this is similar to what I pointed out at #1081 (comment)

Currently, we don't have a way to convert a SciPy sparse array into Rust. We'll need to figure out that first. Implementing the method is trivial, but until we have the conversion we are going to be a bit stuck.

The solution will probably use https://docs.rs/pyo3/latest/pyo3/conversion/trait.FromPyObject.html and call scipy to convert the matrix to a more convenient format we can process, maybe.