nocloud-net doesn't read included network-config file if using seedfrom=URL

[Ryan Harper]

Currently nocloud-net does not process network-config file if included in the seed provided via a URL. This is by-design, however, now that several datasources have this model of using an ephemeral DHCP process to fetch user/metadata, which includes network-configuration and then apply that; nocloud-net could transition to this model.

[James Falcon (falcojr)]

Tracked in Github Issues as https://github.com/canonical/cloud-init/issues/3307