[EGD-5709] Fixed actions support in Call application

Fixed:
- returning from a call window to previous application
- closing SMS templates window if open from call window

[EGD-5709] Add full actions support in call application

Application call used both actions and messages which
caused windows switch problems. It has been refactored
to handle all communication by actions.

[EGD-6958] Fix rssibar oor exception

This commit fixes out of range exception for rssi indication on topbar.

[EGD-6918] Timestamp clean up

Removal of not needed methods
Addition of unit tests
Fixes according to newst design guidelines
Added new seprate interface cmake lib for time constants

[BH-515] Create main Bell app

Create main Bell app

Merge branch 'master' into stable

[BH-373] Convert utils json into a lib

Moving json to a third-party standalone library.

[BH-353] Add Documentation for main targets

* clean up mimimu required cmake version
* fixes for release workflow

Add documentation for targets, fixes for cmake
and release workflow.

[EGD-6544] Switch for VoLTE

Turn off/on VoLTE during compilation

[BH-367] Convert UCS2 to library

Convert UCS2 to library,
move tests from module-utils/test to UCS2 folder

Merge branch 'master' into stable

[BH-376] Utils time turned to separate library

Turned module-utils/time folder content into separate library,
cleaned up CMake libs dependencies, fixed include paths

[BH-370] Convert utils common_data into a libs

Create clipboard and eventsore libs

[BH-369] Turned UTF8 into separate library

Moved utf8 files, formed separate library, fixed include paths,
added utf8 library as dependency to every other target that
uses it, clang-formated utf8 files, cleaned up tests cmake script,
moved utf8 unit test

[EGD-6907] Introduce ModemState in Cellular

We should not use Cellular's internal states to drive
other system parts, especially applications

[BH-378] Utils move log to library

Moved log to separate library

[EGD-6898] Remove dead SimProcedure code

There were leftovers from an earlier SIM initialization procedure

[BH-360] Move TPLIB re2 to separate dir

Changed submodule directory and updated cmake scripts.
Updated paths in PureCoverage script and Doxyfile

[BH-371] Replace gsl with mainline submodule and move to third-party

Replacing loose gsl files with gsl mainline project as submodule
and moving it to third-party

[EGD-6896] Sanitize Tray event handling

Tray events were handled inconsistently with its Message used
in a separate context