helm: Add configurable label selector in StatefulSets volumeClaimTemplates

Is your feature request related to a problem? Please describe.

It would be useful to be able to add selector labels to the PVCs created by the StatefulSets. Right now, when setting up the chart initially, all StatefulSets create their PVCs and the volumes are bound based on Storage Class, Size and Access Modes.

Describe the solution you'd like

For all the StatefulSets:

• alertmanager;
• compactor;
• ingester ;
• store_gateway.

implement configurable label selector in the templates:

File: <component>/<component>-statefulset.yaml:

Under spec -> volumeClaimTemplates[*] -> spec selector: {{ .Values.<component>.persistentVolume.selector }}

File: values.yaml:

<component>:
  persistentVolume:
    selector: {} # empty selector by default

Describe alternatives you've considered

Right now, if you want to hand pick the PVs for the components, you have to enable them one by one in your deployment.

Additional context

None