feat: add relative vector evaluation metric for multimers

[jakublala]

AnalyzePermutations class -- high-level class does everything, including plots.

Make an equivalent of the DockQ evaluation function - lives in utils.py.

Then add it to do_monomer_and_multimer_comparison.

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The approach is to center chain A, then find vectors to chain B and chain C -- always considering the centroids/centres off mass. Then the angle and the magnitude of the vector should be informative.