Issue:
Target network namespace is always the plan target namespace, but it can also be "default"

a. create a plan on namesapce that is not default
b. map a source network to a NAD from the default namespace
expected result:
network mapping is mapped to the default namespace
what happen:
network mapping is mappred to the target namespace

URL: https://github.com/kubev2v/forklift-console-plugin/issues/1171