Elasticsearch Metrics Cat 5

Continuation: https://issues.redhat.com/browse/LOG-1852

As a RH associate, I want to observe OpenShift Logging Log Store metrics across the Elasticsearch fleet, so that I can inform my BU, eng team, etc. about how features are used or which problem areas exists or how big the clusters are.

Acceptance Criteria:

• Periodically scapping elasticsearch prometheus metrics to produce results
• Creation and exposure of the Category 5 metrics describe in this document: https://docs.google.com/document/d/1ek98QDTztWHuYzUX_T53O9JblUtL9-YRMUK5oHMIK8w/edit

Dev Notes:

Current Metrics: https://github.com/openshift/elasticsearch-operator/blob/master/internal/metrics/metrics.go
Similar implementation for Loki just for CR metrics: https://github.com/ViaQ/loki-operator/pull/32