Fix bug in sdnnetwork capability implementation and driver.

- Make internal driver GetAllocatedFlowsAction return an ActionResponse with status set to OK.
- Avoid IndexOutOfRange in OFProvisioningNetworkCapability when creating an ActionException if action response is not OK.
Remove NCL provisioner mockup.

It is no longer necessary.
It was being injected by error in NCLProvisionerTest, instead of actual provisioner.
NCLProvisionerTest now checks sdnnetwork and switches are updated when nclprovisioner is called.
Merge pull request #717 from isartcanyameres/fix/ofertie-ncl-updates-switches

Fix/ofertie ncl updates switches