* Nicely handle missing user in collaborations
It is possible to have a collaboration in a repository which refers to a no-longer
existing user. This causes the repository transfer to fail with an unusual error.
This PR makes `repo.getCollaborators()` nicely handle the missing user by ghosting
the collaboration but also adds consistency check. It also adds an
Access consistency check.
Fix#17044
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: KN4CK3R <admin@oldschoolhack.me>