Remove bonds from configuration on node unnassign

- Bonds should be removed from configuration when node
  unnasigned from cluster
- If no admin network group is found, lookup admin interface
  by cidr only on node.nic_interfaces

This bug partially fixed by previous refactoring

Change-Id: Ibafab7d2aa2a3377a6c184a689a2607b4953ee09
Closes-Bug: #1328163