Add containerdisk imageformat to RNG schema
The containerdisk imageformat is used by KubeVirt to distribute bootable cloud images as container image. [1] This allows for easy distribution of guest images in the KubeVirt scope. Once downloaded, container images are also cached and can be easily reused.
[1] https://kubevirt.io/user-guide/virtual_machines/disks_and_volumes/#containerdisk
Containerdisks are added to:
- centos 7 and stream-[8|9]
- fedora [35|36]
- ubuntu [18.04|20.04|22.04]
Fixes libosinfo#48 (closed)