[watcher] Using watcher without standard Openstack telemetry projects

Hey folks! I am looking at Watcher for a possible integration with an Openstack cloud where : - The Openstack cloud does not have Gnocchi/Ceilometer or the STF from Red Hat. - I am able to get standard libvirt metrics from a compute. Before going too deep, if we assume that we can expose metrics using an OpenMetric/Prometheus format, can Watcher be fed these metrics? Thanks!