convert virt-controller to new `AddFlags` standard
convert virt-controller to new `AddFlags` standard

And also make it a proper service.

Signed-off-by: Martin Polednik <864cc392241c077e6ac82cfafc3cb7cecb8321ba@redhat.com>

rmohr/kubevirt,stu-gott/kubevirt,davidvossel/kubevirt,davidvossel/kubevirt,rmohr/kubevirt,fabiand/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,davidvossel/kubevirt,kubevirt/kubevirt,stu-gott/kubevirt,stu-gott/kubevirt,davidvossel/kubevirt,stu-gott/kubevirt,fabiand/kubevirt