[wl/tmp] Support loopback interface (v2)
Support managing the loopback interface through NM as the users want to set the proper mtu for loopback interface when forwarding the packets. Additionally, the IP addresses, DNS, route and routing rules are also allowed to configure for the loopback connection profiles.
https://bugzilla.redhat.com/show_bug.cgi?id=2060905
This is a continuation of !1287 (closed).