test(getinstdisk): cover the install disk selection order

Run the real scripts in a sandbox. A stub udevadm serves the device
properties from fixture files, and the partition list and the output
paths move into the sandbox. Every case runs against the common script
and against the copy the RHEL 10 installer includes.

Cover the direct attached disk against a RAID volume, a RAID only
server, the host adapter against a direct attached disk and against an
unknown driver, an NVMe device from the last group, and the default
fallback. Against the previous scripts the RAID cases fail, so they
discriminate.