Future Idea: Subcommand to create a plug&play USB-Stick image

At the moment the most final artifact that is created by stmgr is an UKI (wrapped in an ISO) Sidenote: The ISO format could be misleading, as some might think, this is bootable right away.

It could be valuable to let stmgr create an image which can be dd to and USB stick and be ready to work with UEFI firware