engine: Extract AddNetworksByLabelParametersBuilder

The class will be used for attaching networks to host
when networks is assigned to a cluster.

Change-Id: I6510892f217c0472d6d79ab5884bb9c082a58bf1
Bug-Url: https://bugzilla.redhat.com/1054195
Signed-off-by: Moti Asayag <masayag@redhat.com>