Do not fetch all public groups for approval rule when search is empty
Description
This is an unexpected UX issue with https://gitlab.com/gitlab-org/gitlab-ee/issues/11194.
Since the groups in a approval rule search are not filtered by the user or project, it includes everything public in the GitLab instance. This is undesirable on .com
when an initial search, loads a bunch of random groups (some of which look pretty sketch).
Edited by Paul Slaughter