Implement more methods of the network API

Open-WebOS-DCO-1.0-Signed-Off-By: Simon Busch <morphis@gravedo.de>
Implement all required fields for isTelephonyReady API method response

Open-WebOS-DCO-1.0-Signed-Off-By: Simon Busch <morphis@gravedo.de>
Implement missing methods for ofono's network service

Open-WebOS-DCO-1.0-Signed-Off-By: Simon Busch <morphis@gravedo.de>
Implement deviceLockQuery and chargeSourceQuery API methods

Signed-off-by: Simon Busch <morphis@gravedo.de>