Add prometheus metrics for postgres operator himself

[teimyBr]

• **Which image of the operator are you using? postgres-operator:v1.8.2
• **Where do you run it - cloud or metal? Kubernetes Bare Metal K8s
• Are you running Postgres Operator in production? yes
• Type of issue? feature request

Add prometheus metrics for postgres operator himself

As a Cluster Operator we want to monitoring the operator and no only the databases.

For his we need metrics we can monitoring in grafana/prometheus

There is already a PR #1529

Background: We want Alerts for Sync Failed and also monitoring how many pg istances the postgres operator is managing