[MOS-977] Added VoLTE support in additional countries

Added VoLTE support in Poland, Germany, Denmark, United Kingdom,
 Netherlands, Canada and Austria.

[MOS-636] Added MMI/USSD confirmation

USSD/MMI codes are now confirmed after they are sended.

[MOS-177] Fix request factory UT are uncommented

Cellular call request factory unit test was commented out
due to failing cases. After MOS-944 failng cases are updated
and all tests are passing.

[MOS-924] Fix redundant logs about CSQ reporting mode

When the modem was turned off (e.g. due to a discharged battery),
CSQ reporting mode logs caused logger buffer overflow.

[MOS-944] Fixed handling USSD started by #

Now call request begins with # character is dicoverd
and handled as a USSD code.

[MOS-960] Fixed SMS flow after failed try in Offline

SMS handling is now fixed after attempt to send SMS in offline mode.
After SMS was rejected by Offline mode, Pure was not able to send
any message until device reboot.

[MOS-47] Fixed non closed USSD session

USSD pull session was not closed when USSD popup
was closed by back button. Also USSD code was slightly
refactored.

[MOS-879] Fixed misleding SMS flow

Fixed misleading SMS flow after sending error.
When modem was rebooting attempt to send SMS was causing
Rejected by no sim popup, which was misleading for user.

[MOS-29] Fix invalid screen after missed call

Fix of the issue that missed call triggered
view that shown 'call ended' text.

[MOS-483] Import SIM card contacts properly

According to information elaborated by Quectel, the contacts don't have
to be saved on a SIM card contiguously and the only way to make sure all
of them are imported is to request for the range [1, 250] (first to
biggest allowed index).

[MOS-870] Fix undesirable notification on call

Fixed the case when a dot appeared around the Calls app
tile notifying about an answered call.

[MOS-840] VoLTE switch unavailability fix

Added checking if a SIM card is present in the active slot
during ApplicationSettings initialization so that in case
there's no SIM, the VoLTE switch is made anavailable to
toggle.

[MOS-807] Unpacking update package

* Added unpacking and validating of
update package
* Removed 'utils-bootconfig'
* Added 'tar' module
* Minor compilation issues fixed

[MOS-869] Correct typo in file name

Now (correctly): 'TetheringHandler.cpp'

[MOS-812] Improved CUSD message handling

* Added handling for shorter +CUSD formats, thus got rid of a crash.
* Added handling for the "push session"+"action required" state of a
  USSD interaction with the network.

[MOS-840] Render VoLTE unavailable if no SIM card

Also, done a minor code cleanup.

[MOS-813] Emergency calling fixed

User is now able to make emergency call with no sim card
inserted. RF functionality in modem is still disabled
until sim card is selected by user.

[MOS-810] Fixed call state timer termination

Fixed the problem that the call state polling
timer wasn't terminated in some cases, so the
modem command AT+CLCC had still been issued
until e.g. another call was made. In such cases,
this lead to inability for the modem to go to
a power-down state due to constant activity and
thus lead to battery power waste.

Additionally, fixed a hidden bug that TimerRing
hadn't got a virtual destructor.

Also thrown out some dead code.

[MOS-655] USSD body in log

USSD body is printen in log, it will help to solve some customer issues.

[MOS-839] Fix crashes after a few VoLTE toggles

Those were occuring after calls which were preceded by
a few VoLTE on/off toggles.