tests,network,expose:extract dup' code to helpers
tests,network,expose:extract dup' code to helpers

Make the expose test code cleaner by extracting some repeated code segments
to helpers.

Signed-off-by: alonsadan <17e3534da4e06ee40320bd1687715e3dda4806ac@redhat.com>

kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt