Add reverse Cuthill-McKee ordering for graphs

[dcoudert]

Fixes #13583.

We add the reverse Cuthill-McKee (RCM) ordering for graphs. We already had Cuthill-McKee and King.

sage: from sage.graphs.base.boost_graph import bandwidth_heuristics
sage: bandwidth_heuristics(graphs.PathGraph(10))
(1, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
sage: bandwidth_heuristics(graphs.GridGraph([3,3]))
(3, [(0, 0), (1, 0), (0, 1), (2, 0), (1, 1), (0, 2), (2, 1), (1, 2), (2, 2)])
sage: bandwidth_heuristics(graphs.GridGraph([3,3]), algorithm='reverse_cuthill_mckee')
(3, [(2, 2), (1, 2), (2, 1), (0, 2), (1, 1), (2, 0), (0, 1), (1, 0), (0, 0)])
sage: bandwidth_heuristics(graphs.GridGraph([3,3]), algorithm='king')
(3, [(0, 0), (1, 0), (0, 1), (2, 0), (1, 1), (0, 2), (2, 1), (1, 2), (2, 2)])

If needed, we can also expose methods bandwidth and bandwidth_heuristics in graphs.

📝 Checklist

• The title is concise, informative, and self-explanatory.
• The description explains in detail what this PR is about.
• I have linked a relevant issue or discussion.
• I have created tests covering the changes.
• I have updated the documentation accordingly.

⌛ Dependencies

[github-actions]

Documentation preview for this PR (built with commit beb275a; changes) is ready! 🎉

[tscrim]

LGTM.

[dcoudert]

Thank you.