Allow to annotate the PodMonitor resource

[dannyyy]

Currently, the Helm chart only allows adding additional labels with podMonitorAdditionalLabels. Could you extend the Helm chart to also add additional annotations (e.g. podMonitorAdditionalAnnotations?

I'm using VictoriaMetrics which creates a VMPodScrape resource from any PodMonitor (same for ServiceMonitor). In conjunction with ArgoCD, this causes an issue because the actual and target state deviates, since the VMPodScrape is created and maintained by the VictoriaMetrics operator.

Therefore, I need to annotate the PodMonitor with argocd.argoproj.io/compare-options: IgnoreExtraneous. Otherwise I'm running constantly in synchronization issues.