Feature request: diagnostic tools for evaluating quality of graph matching

[Eric Bridgeford]

Is your feature request related to a problem? Please describe.

For networks with a known correspondance, a match ratio can be constructed; e.g., where P is the correct permutation matrix and Pu is the calculated permutation matrix, just sum the number of times the diagonal of PPu = 1.

[Ben Pedigo]

I have a bunch of code for this and other diagnostics, down to add them after #960 is approved