dual stack, expose, tests: get the IP addr from a DNS name
dual stack, expose, tests: get the IP addr from a DNS name

Provide functions to retrieve the IP address (of a given IP family)
of a given DNS name. The address is resolved within the cluster.

These functions will be used as a work-around on the next patches,
since the `Node` API does not return all the IP addresses of its
nodes.

The aforementioned issue is tracked in kubevirtci, by issue [0].

[0] - https://github.com/kubevirt/kubevirtci/issues/462

Signed-off-by: Miguel Duarte Barroso <c798d3f0e4fda7badfc3bbd91babde7ebd48b6c2@redhat.com>

davidvossel/kubevirt,davidvossel/kubevirt,kubevirt/kubevirt,stu-gott/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt,davidvossel/kubevirt,davidvossel/kubevirt,stu-gott/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,stu-gott/kubevirt