This is mostly boot tooling, the integration test is just one instance
making use of it.
Expose initrd, kernel and runVM as a separate target to CI, and move the
tests to a subdirectory.
Change-Id: I1d22cd68bf5af095bc11dd9d7117b62956c7f7f2
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9465
Reviewed-by: raitobezarius <tvl@lahfa.xyz>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI
