Kubernetes shared storage integration

The SDP needs to be able to access the same datasets between different running processes and different namespaces within Kubernetes, in order to be able to distribute the processing across the cluster.  Whilst this is possible to do manually, it does require privileged access to the underlying Ceph storage service to create the initial CephFS subvolume, that is then used across multiple PersistentVolumes.  A more productive solution is to create a plugin that enables PersistentVolumes to be dynamically created that handle the negotiation of the shared subvolume, making the process self-service.