[Story] Integrate directly with Grafana

[andrewazores]

See cryostatio/cryostat-grafana-dashboard#25

[andrewazores]

Deprioritized for this release. cryostatio/cryostat-grafana-dashboard#68 will get us back onto a non-deprecated path at least, which is enough to continue on with the same jfr-datasource/grafana-dashboard setup. This issue is more about changing the jfr-datasource functionality so that it no longer needs a separate Grafana plugin like simple-json/infinity, and/or rolling the jfr-datasource functionality directly into Cryostat so that it links to Grafana directly. That's a nice optimization goal and would probably also help with multi-file comparison, but it isn't strictly required to unblock the next release.