Add new cases of libvirtd

[chloerh]

• VIRT-300392 - Enable/disable daemons socket services
• VIRT-300393 - Check the socket files after start/stop daemons' socket service
• VIRT-300394 - Check virsh connection after switching between the legacy monolithic daemon and the modular daemon

Test result:

 (1/6) type_specific.io-github-autotest-libvirt.daemon.check_virsh_connection_switch_between_monolithic_and_modular: PASS (6.54 s)
 (2/6) type_specific.io-github-autotest-libvirt.daemon.enable_disable_daemon_socket_services.main_socket: PASS (14.20 s)
 (3/6) type_specific.io-github-autotest-libvirt.daemon.enable_disable_daemon_socket_services.ro_socket: PASS (14.13 s)
 (4/6) type_specific.io-github-autotest-libvirt.daemon.enable_disable_daemon_socket_services.admin_socket: PASS (14.20 s)
 (5/6) type_specific.io-github-autotest-libvirt.daemon.enable_disable_daemon_socket_services.only_virtproxyd: PASS (6.61 s)
 (6/6) type_specific.io-github-autotest-libvirt.daemon.check_socket_files_with_services: PASS (6.30 s)
RESULTS    : PASS 6 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0