qemu: Report shutdown event details

qemu: Report shutdown event details

QEMU will likely report the details of it shutting down, particularly
whether the shutdown was initiated by the guest or host.  We should
forward that information along, at least for shutdown events.  Reset
has that as well, however that is not a lifecycle event and would add
extra constants that might not be used.  It can be added later on.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1384007

Signed-off-by: Martin Kletzander <mkletzan@redhat.com>