[feat] provide health and performance metrics

[freeznet]

possible metrics:

• cluster wide
  • start time (cold start)
  • resource count / running count / etc.
  • controller resources (CPU, memory)
  • resource reconciliation time https://github.com/streamnative/function-mesh/pull/689
• resource
  • start time
  • component status (sts, service, hpa, vpa: ready, etc)
  • replicas

references:

• https://sdk.operatorframework.io/docs/best-practices/observability-best-practices/
• https://github.com/kubernetes/kube-state-metrics/blob/main/internal/store/pod.go
• https://sdk.operatorframework.io/docs/overview/operator-capabilities/#monitoring