Reduce duplication in Neutron reclass

  * Common definitions moved to neutron/control/cluster.yml
                               neutron/control/single.yml
  * neutron/control/cluster.yml and neutron/control/single.yml
    defined in conforming backend ones.

Change-Id: I9bf580c70a886db7188716f96d48f1d2a2d3a2a1
8 files changed