There could be either wired (metalic, SFP) or wireless (QMI) interface designated as WAN.
Therefore we need to provide settings for both types in the 'api/wan' GET request to be able to fill in the wan settings form.
This MR resolves part of #273 (closed)
Depends on: turris/foris-controller/foris-controller-wwan-module!1, turris/foris-controller/foris-controller!125