v2v: collect source network and video adapter types

Those will be useful when making decisions about what configuration to
set on output.

The data is also included in --print-source so the tests are adjusted
accordingly.

Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: "Richard W.M. Jones" <rjones@redhat.com>

test-data/phony-guests/guests.xml.in

@@ -276,6 +276,14 @@
         <source file='@abs_builddir@/windows.img'/>
         <target dev='vda' bus='virtio'/>
       </disk>
+      <interface type='network'>
+        <mac address='00:11:22:33:44:55'/>
+        <source network='default'/>
+        <model type='virtio'/>
+      </interface>
+      <video>
+        <model type='qxl' ram='65536' vram='65536' vgamem='16384' heads='1'/>
+      </video>
     </devices>
   </domain>