refactor(*): migrate some files to bundled ring homs (#2133)
* refactor(*): migrate some files to bundled ring homs
* Rename ring_hom.is_local back to is_local_ring_hom
* Apply suggestions from code review
Co-Authored-By: Johan Commelin <johan@commelin.net>
* Restore 2 instances, make `map` use bundled homs
* More bundled homs
* Add a docstring
Co-authored-by: Johan Commelin <johan@commelin.net>
