Inclusion of More Centrality Measures and Internal Indices

##### Expected behavior
Currently the more niche Centrality Algorithms are missing from NetworkX https://github.com/networkx/networkx/issues/4973 and iGraph https://github.com/igraph/igraph/issues/1741

Even when those are ignored, there are still some that are worth mentioning for Orange3 from NetworkX:

For Node-Pair Centrality
- https://networkx.org/documentation/latest/reference/algorithms/link_prediction.html
- https://networkx.org/documentation/latest/reference/algorithms/communicability_alg.html
- https://networkx.org/documentation/latest/reference/algorithms/assortativity.html

For Clustering Indices
- https://networkx.org/documentation/latest/reference/algorithms/clustering.html
- https://networkx.org/documentation/latest/reference/algorithms/centrality.html
- https://networkx.org/documentation/latest/reference/algorithms/dominance.html
- https://networkx.org/documentation/latest/reference/algorithms/link_analysis.html
- https://networkx.org/documentation/latest/reference/algorithms/structuralholes.html

Start by reviewing the linked NetworkX documentation and the referenced NetworkX and iGraph issues to compare the proposed centrality and clustering measures. The issue names no repository files or tests, so first establish which measures and Orange3-network entry points are in scope; done should mean the selected measures are implemented and their behavior is verified.

Written by the indexing model from the issue text.