If there is a single connection for a given NMToggle subclass,
use the connection name; otherwise, transform that into '%d
connected'. This is better than the current "Device (counter)"
template, e.g. "VPN (2)", which would give us a quick toggle
with:
VPN
VPN (2)
Change that to e.g.:
VPN
2 connected
Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2619>