gh-36701: some details in combinations
mainly making the cardinality sage integers and running the `TestSuite`
also adding a few type annotations
### :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 created tests covering the changes.
- [x] I have updated the documentation accordingly.
URL: https://github.com/sagemath/sage/pull/36701
Reported by: Frédéric Chapoton
Reviewer(s): David Coudert
