Add CDI unit with kubevirt to use it for importing disk images

Containerized Data Importer

CDI provides facilities for enabling Persistent Volume Claims (PVCs) to be used as disks for KubeVirt VMs by way of DataVolumes

• Import a disk image from a web server or container registry to a DataVolume.
• Clone an existing PVC to a DataVolume.
• Upload a local disk image to a DataVolume.

CDI supports the raw and qcow2 image formats which are supported by qemu

Image can be uploaded to data volume by `virctl`` command

There can be a separate unit required for CDI to use with kubevirt

Related RFE: sylva!51 (closed)