This does pretty much the same things as the AMI compose type, but also
replaces NetworkManager with the Azure linux agent.
(cherry picked from commit e0c236ff36)
This differs from lmc's --make-ami in that creates a full disk image instead of
an fsimage. Create a raw disk image with a / and /boot partitions, and enable
sshd, chronyd, and cockpit by default.
(cherry picked from commit 18188bf6cf)
Currently we are making MBR disk images for qcow2 and partitioned disk,
so the UEFI packages aren't required at this point.
Move the clearpart command into compose.py so that in the futute it can
use clearpart --disklabel to create a GPT image, and add the required
packages to the package set.
