self-describing issue.
added a friend as a test and now I want to remove the collaborator status, nothing in UI shows the ability to remove a collaborator.
this is somewhat related to #340 but I would say even if it's not redesigned, the current way the feature exists as-is is incomplete. the codebase does have enforcer.DeleteCollaborator() but it's just only called from repo.DeleteRepo(), rather than anywhere on API or appview/ingester.