Create CI/CD-only projects by URL FE

Merged Eric Eastwood requested to merge 3839-ci-cd-only-projects-fe into master

What does this MR do?

CE backport: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/17342

BE: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4567

Are there points in the code the reviewer needs to double check?

Does this MR meet the acceptance criteria?

What are the relevant issue numbers?

Closes #3839 (closed)

Edited by Eric Eastwood