[lr/complete-conn] Prefer using interface name when completing a connection
In general, we should prefer defaulting to an interface name when completing a connection instead of a mac address.
The connections get completed on user either clicking on an interface name in the UI, or doing something like
nmcli d connect <interface name>. The point is that the user specifies the name, and that the hardware address ends up in the connection is somewhat unexpected.
This makes sense even more so that the interface names tend to be stable.