Revert "Enrich commits with full data in CommitCollection"
This reverts https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/26144 from CE due to https://gitlab.com/gitlab-org/gitlab-ee/issues/10567.
This reverts https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/26144 from CE due to https://gitlab.com/gitlab-org/gitlab-ee/issues/10567.