sage

157a645e -

gh-37072: some cleanup in overconvergent and quaternion Two different things: - cleaning the file `overconvergent/genus0`, adding a `TestSuite` and making it pass ; getting rid of non-sensical `gens_dict` there - making quaternion algebra return a tuple of generators ### :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. URL: https://github.com/sagemath/sage/pull/37072 Reported by: Frédéric Chapoton Reviewer(s): David Coudert, Frédéric Chapoton