gh-35990: Working MCDS implementation using connectivity constraints
Extended `dominating_sets` to be able to generate Minimum Connected
Dominating Sets using connectivity constraints. This functionality can
be toggled on by setting the `connected` parameter flag to true.
Fixes #35989.
### :memo: Checklist
- [x] The title is concise, informative, and self-explanatory.
- [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 accordingly.
URL: https://github.com/sagemath/sage/pull/35990
Reported by: Jared Smith
Reviewer(s): David Coudert
