Optimized connectivity: Simultaneous face_edges and edge_nodes

[cmdupuis3]

Would close #1138, #1196

Related to #1180

Supercedes #1195

Overview

This set of changes optimizes face_edge, edge_node, and face_face connectivity. face_edge and edge_node connectivity are combined into one routine, while face_face is optimized stand-alone.

PR Checklist

General

• An issue is linked created and linked
• Add appropriate labels
• Filled out Overview and Expected Usage (if applicable) sections

Testing

• Adequate tests are created if there is new functionality
• Tests cover all possible logical paths in your function
• Tests are not too basic (such as simply calling a function and nothing else)

Documentation

• Docstrings have been added to all new functions
• Docstrings have updated with any function changes
• Internal functions have a preceding underscore (_) and have been added to docs/internal_api/index.rst
• User functions have been added to docs/user_api/index.rst

Examples

• Any new notebook examples added to docs/examples/ folder
• Clear the output of all cells before committing
• New notebook files added to docs/examples.rst toctree
• New notebook files added to new entry in docs/gallery.yml with appropriate thumbnail photo in docs/_static/thumbnails/

[cmdupuis3]

I think all the hard parts of the merge are done.

At this point, the only failures seems to be sorting issues.