feat: allow defined container volumes

[acamilleri]

Hello

This PR allows users to configure custom volumes to be mounted in the operator container, this is needed to mount a custom CA from a secret into the container as a file and use it them with the caCertificateBundlePath arg instead of using the caCertificatesBase64 arg.

values:
    s3:
      caCertificateBundlePath: "/etc/certificates/ca.crt"
    controllerManager:
      manager:
        volumes:
          - name: custom-ca
             secret:
               secretName: custom-ca-bundle
        volumeMounts:
          - name: custom-ca
             mountPath: /etc/certificates
             readOnly: true