[RILMODEM] initial support to read and delete sms from sim (class2, voicemail mwi)

Provides initial support for reading sms stored on sim and deleting them. If a new sms is stored on sim ofono rilmodem driver will read it, forward it as normal sms to ofono core and then delete the sms from sim.

Signed-off-by: Jarko Poutiainen <Jarko.Poutiainen@oss.tieto.com>