Need possibility to add annotations into PVC

[centaurea-riba]

Problem

For solve technical problem we need add "helm.sh/resource-policy": keep into PVC annotations, but there are no variables in cluster Helm chart for CNPG, schema allow only:

 storage:
   size: 
   storageClass:

 walStorage:
   enabled:
   size:
   storageClass:

it will be nice to have something like:

 storage:
   annotations:
     some: some
   size: 
   storageClass:

 walStorage:
   annotations:
     some: some
   enabled:
   size:
   storageClass:

We try to do

We need it for keep PVC after helm/helmfile uninstall from cluster, to make next workflow workable:

• apply Helm chart;
• use CNPG;
• uninstall CNPG for maintenance things;
• apply Helm chart again;
• it start use the same PVC as in previous (due usage of Longhorn it not trivial task to create PV/Volume with fixed naming).