Fork into Developer Namespace

Summary

When trying to fork a repository into a new namespace, only those with at least Maintainer rights are listed.

Steps to reproduce

1. Create new group
2. Add new member with developer rights
3. Login as that user
4. Fork some visible project
5. See that the newly created group is not available as fork namespace

What is the current bug behavior?

Fork is impossible

What is the expected correct behavior?

Fork should be possible (https://docs.gitlab.com/ee/user/project/repository/forking_workflow.html#creating-a-fork).

Results of GitLab environment info

Expand for output related to GitLab environment info

 GitLab Community Edition 13.5.4