Add a clearlinux workload

[markdryan]

It would be nice if ccloudvm worked with clearlinux.

There's a bunch of things we'll need to fix first.

• We need to be able to handle compressed images.
• We need to support efi boot
• We need to be able to set dnssearch so autoproxy works
• Figure out a way of getting runcmd to work (https://github.com/clearlinux/micro-config-drive/issues/24)