Review NodePool metrics and set some internal SLOs/SLIs

Follow up for https://issues.redhat.com/browse/HOSTEDCP-969

Create metrics and grafana panel in

https://hypershift-monitoring.homelab.sjennings.me:3000/d/PGCTmCL4z/hypershift-slos-slis-alberto-playground?orgId=1&from=now-24h&to=now

https://github.com/openshift/hypershift/tree/main/contrib/metrics

for NodePool internal SLOs/SLIs:

• NodePoolDeletionDuration
• NodePoolInitialRolloutDuration

Move existing metrics when possible from metrics loop into nodepool controller:

- nodePoolSize

Explore and discuss granular metrics to track NodePool lifecycle bottle necks, infra, ignition, node networking, available. Consolidate that with hostedClusterTransitionSeconds metrics and dashboard panels

Explore and discuss metrics for upgrade duration SLO for both HC and NodePool.