GitHub importer: respond with detailed errors info
Problem
It's a backend part for Show end state of the import and detailed information on not imported entities to the user.
At the moment, we show Partial import
badge in UI. The badge should be renamed to Partially completed
and the UI report visible on import/history
and import/github/status
pages expanded to show list of entities (links) that were not imported:
Proposal
What we want is to have separated page with detailed status and list of errors that happened during the import (similar to history page for GitLab migration). Also would be nice to have a list of links for each entity on GitHub side that we failed to import (if such link exists for this entity).
Technical details
New endpoint with paginated list of import errors for each particular entity.