Add WiFi APs selection to quick settings

When a user long presses the WiFi QuickSetting in the top panel, it will show the list of available devices, which, then can be activated.

TODOs

• Disable the wifi status on the lock screen
• GtkSwitch in the status to disable wifi (could be a follow up)
• When in hotspot mode don't list the Wifi networks (we can e.g. allow to turn it off)