libvirt: Add hypervisor variants for libvirt in tests-shared.cfg

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
libvirt: New sub module for libvirt_python.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>
libvirt_python: Add test for open() function in libvirt_python.

Signed-off-by: Dongsheng Yang <yangds.fnst@cn.fujitsu.com>