Show general end state of migration process: Completed, Partially completed, Failed

Problem

At the moment, in UI upon finished migration process of a top-level group we show badge "Complete" or "Failed" next to each migrated group. However "Complete" is shown also for migrations that were not fully completed - there were errors and some resources didn't get migrated.

Proposed solution

To be more precise, we should show general end state of migration process with 3 badges:

• green "Completed" - when all resources were successfully imported (Q: Is it still possible to have any errors in this case?)
• orange or yellow "Partially completed" - when some resources failed to be imported, but migration in general was successful, as in group, subgroups and projects structure were created, many resources got imported
• red "Failed" - migration was unsuccessful, no resources got migrated, group was not created.

Show one of possible end statuses (Completed, Partially completed, Failed) in API response as well.

Document what each status means.