network: Update "Wired" section UI

The current "Wired" section UI is still optimized for
the old, multi-page panel layout. Recent work [1],
however, suggest that this should change and the standard
widgets be rearranged.

This commit, then, implements this new UI for the wired
devices UI by using a listbox row when there's only one
profile (ditching out the old info labels), and moving
and deleting the bottom action buttons.

https://bugzilla.gnome.org/show_bug.cgi?id=785581