Add RIB routes for automatically created permanent faces
When a network interface card (NIC) is added to the system, NFD can automatically create Ethernet and UDP multicast faces (#2460) and NIC-associated permanent faces (#3521).
However, NFD lacks a mechanism to automatically add RIB routes for those faces, and a face without routes isn't useful for Interest forwarding in most strategies.
This issue is to develop a procedure to configure zero or more RIB routes to be added when a face is automatically created.
There would be no need to refresh those routes, because permanent faces can survive link failures and local IP address changes.