UpdateSWH per rdicosmo

This extension checks if a software development repository visited by the user in a supported code hosting platform is archived and uptodate in Software Heritage. A color button on the right of the browser indicates if it is uptodate (green), in which case clicking on the button opens a tab on the corresponding page of the archive, missing (grey) or not up to date (yellow), in which case clicking on the button triggers a save code now request, and optionally shows the save request submitted to the Software Heritage archive.

A red color indicates that the API request of information for the repository did not succeed: this happens typically when one is visiting a repository that is not publicly accessible, and that naturally cannot be archived.