qapi: add native list coverage for QMP input visitor tests This exercises schema-generated visitors for native list types and does some sanity checking on validity of deserialized data. Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Amos Kong <akong@redhat.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>