Automatically set `quota-backend-bytes` option to 95% from requested size:

[kvaps]

eg.:

spec:
  storage:
    volumeClaimTemplate:
      metadata: {}
      spec:
        accessModes:
        - ReadWriteOnce
        resources:
          requests:
            storage: 20Gi

should also implicitly set:

spec:
  options:
    quota-backend-bytes: "20401094656"

also we have to check if this option not applied by user explicitly

currntly we do this with Helm, see https://github.com/aenix-io/cozystack/pull/133/files