API: Proxy neutron configuration to guest instance

Currently the metadata service only contains minimal network
information. Like user_data and vendor_data, we should also provide
network_data. Really we should provide all the information we can
(from neutron) in both config drive and metadata service.

blueprint metadata-service-network-info

Change-Id: Ia6967af4b4147ad4dcf6ae3ae5f4b6d9c1fda246
Co-Authored-By: Josh Gachnang <josh@servercobra.com>
Merge "API: Proxy neutron configuration to guest instance"