Modify network creation to add slice to its SliceProvider. Do not call reservation capability.

- Wrapper for the network resource (virtualNetwork)
- Do not call reservation capability: Nitos IRequestBasedNetworkManagement capability will reserve its devices, and the other resources will be "reserved" by creating a slice. We assume the reservation will be immediately done. (This wil change after the demo)

Commented code contains first version of the request for the nitos IRequestBasedNetworkManagement creation. Stil to be improved.