Implemented methods pertaining to the canonical partition of a matching covered graph

[janmenjayap]

The objective of this issue is to implement the methods pertaining to the canonical partition of a matching covered graph.

More specifically, this PR aims to implement the following two methods:

• [x] maximal_barrier(): Return the (unique) maximal barrier containing the provided vertex.
• [x] canonical_partition(): Return the canonical partition of the (matching covered) graph.

This PR shall address the methods related to canonical partition of matching covered graphs.

Fixes #38216. Note that this issue fixes a small part of the mentioned issue. This PR depends on the PR #38742.

:memo: Checklist

• [x] The title is concise and informative.
• [x] The description explains in detail what this PR is about.
• [x] I have linked a relevant issue or discussion.
• [x] I have created tests covering the changes.
• [x] I have updated the documentation and checked the documentation preview.

:hourglass: Dependencies

Nothing as of now (up to my knowledge).

cc: @dcoudert.

[github-actions[bot]]

Documentation preview for this PR (built with commit ee8bdbd28f853b3a8b7a771056c8bb4ca6c4e01c; changes) is ready! :tada: This preview will update shortly after each push to this PR.

[dcoudert]

in the description of this PR, you say that it fixes #38216 but this is not the case. It is part of that issue, or a follow-up of that issue.