Cross-checking functions to find unique additions

[biphy]

I implemented an alternative algorithm to find all unique single-edge additions to a circular interaction network, network_utilities/unique_cycle_addition. Although the applicability of this algorithm is limited (it only applies to counting additions of a single edge to a circular base topology), it can be used to cross-check the existing function network_utilities/unique_network_additions.

It is expected that the following functions give the equal sets of the connectivity matrices:

connectivity_vector1 = unique_network_additions(connectivity, 1)
connectivity_vector2 = unique_cycle_addition(connectivity)

I also implemented a function to check if two vectors of connectivity matrices are equal:

is_same_set_of_networks(connectivity_vector1, connectivity_vector2)

Relevant tests are added as well.