AdwActionRow handles many of the properties we use
CcListRow for. We can re-use it instead of re-creating it.
CcListRow is now an AdwActionRow with three suffixes.
The `activatable-widget` is set when the switch is visible.
Since our `icon-name` property was only used for the arrow
icon, it has been replaced with a `show-arrow` property.
The `bold` property has been removed - it was only used in
one place, and it's not a pattern used in other apps.
I decided to go this route because replacing all the
instances of CcListRow with AdwActionRow directly would
end up being more code.
The panel supports 2G/3G/4G GSM/LTE modems. CDMA2000 Modems are not supported.
If a supported modem is present, the panel will be shown and the modem will be
handled, else, network-panel shall manage the modem as it did in the past.
If more than one modem with data enabled is present, the user is allowed to set
priority of one SIM over the other (the priority is for SIM, not modem).
Fixes https://gitlab.gnome.org/GNOME/gnome-control-center/issues/132
