stackgres-operator Helm chart: allow to configure resources for operator, restapi and amdinui containers

When installing stackgres-operator chart, there is no resources definition for the containers in operator and webapi deployments.

This puts the pods in BestEffort Quality of service class.

A user should be able to set resources for each container, to improve the quality of service for the pods.

The solution could be as following:

• For each one of operator, jobs, restapi and adminui entries: Add a resources object, empty by default, in values.yaml
• In the respective containers definitions, add something like the following:

{{- with .Values.operator.resources }}
  resources:
{{- toYaml . | nindent 12 }}
{{- end }}