Add access level param to CA group filter

What does this MR do?

Adds an additional param which is required in order to restrict displayed groups - this is urgently needed for https://gitlab.com/gitlab-org/gitlab-ee/issues/12753

The changes from this MR are going to be replaced by a major refactor https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/15039 😱

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Style guides
• Separation of EE specific content