Add issue numbers to list of unreplicated types

Following on from https://gitlab.com/gitlab-org/gitlab-ee/issues/12398 where we compiled a list of unreplicated types that is now visible here (https://docs.gitlab.com/ee/administration/geo/replication/index.html#limitations-on-replicationverification), we should add issues to the list of unreplicated types so that customers can follow our progress for supporting these types.