[kube-monitoring] Ensuring prometheus-operator uniqueness per cluster

[richardtief]

Context

kube monitoring deploys an umbrella chart including the prometheus operator and it's CRDs. When instantiating the plugin multiple times for additional Prometheus (horizontal scaling), the operator and CRDs should not be deployed again or at least a check should be made in the cluster to see whether it is already installed. In addition, the alerts plugin is dependent on the operator + CRDs - but can also deploy it independently.

Acceptance criteria

1. Ensuring prometheus-operator uniqueness per cluster
2. Tests
3. Dokumentation

[github-actions]

This issue is stale because it has been open for 90 days with no activity.