Most of the dashboards in grafana are designed to have a cluster per DC, we need to refactor them so that we can select a specific cluster.

e.g. https://grafana.wikimedia.org/d/000000461/elasticsearch-indexing-prometheus?orgId=1 should include a drop-down menu to select between chi (current prod instance), psi or omega.

For now we should only rework graphs where the metrics that are extracted directly from elasticsearch, MediaWiki and CirrusSearch metrics may not report the cluster name in a useful way yet.