Report additional network information with network status notification

Open-webOS-DCO-1.0-Signed-off-by: Simon Busch <morphis@gravedo.de>
Don't return boolean but string instead when reporting power state change

Open-webOS-DCO-1.0-Signed-off-by: Simon Busch <morphis@gravedo.de>
ofono: rework property notification interface to be more generic

Open-webOS-DCO-1.0-Signed-off-by: Simon Busch <morphis@gravedo.de>
ofono: report network status update when current network names changes

Open-webOS-DCO-1.0-Signed-off-by: Simon Busch <morphis@gravedo.de>
Don't send network status updates when about to powering of the service

Open-webOS-DCO-1.0-Signed-off-by: Simon Busch <morphis@gravedo.de>