Improve `virsh start --console` behavior

Improve `virsh start --console` behavior

When starting a guest via libvirt (`virsh start --console`), early
console output was missed because the guest was started first and then
the console was attached. This patch changes this to the following
sequence:

1. create a paused guest
2. attach the console
3. resume the guest

Reviewed-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Signed-off-by: Marc Hartmayer <mhartmay@linux.ibm.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>