[EGD-6950] Added header layout

Added Header Layout.

[EGD-6697] Date and time formatting

Added system locale dependant date and time formatting.

[EGD-6960] Header addition related style cleanups

Header addition related style cleanups.

[BH-501] MainMenu

Add Bell main menu window and option menu

[BH-459] Moved fatfs to third-party v2

2nd approach to moving fatfs to third-party. Declared as INTERFACE.

[EGD-6797] Remove color from SAR

Colors are not handled properly during scrolling so use only black

[EGD-6952] Fix tethering on low battery

Added prevention of tehering mode change
while battery is below critical level

[EGD-6954] Enable all unit tests

As all unit tests are working now, there'
s no need to create a list with tests to execute

[EGD-6876] Fix Factory Settings Test

Fixed factory settings test - the query path was wrongly created

[CP-200] Delete file with old OS version

Removed update file after a successful update or
in case of an interrupted download.

[CP-200] Revert Delete file with old OS version

This reverts commit e6de85dbc19963e77144b192b9f40fbdc25a7e0d.

[BH-372] Turned i18n into separate library

Turned i18n module into separate library moving source files, test
files and creating separate CMakeLists.txt, fixed other modules
link targets, fixed paths and sorted some lists

[BH-374] Librarize application-antenna

Add apps-common, librarize application-antenna

[CP-200] Delete file with old OS version

Removed update file after successful update

[EGD-6947] Fix SQL vulnerabilities

These were potential security holes allowing SQL injections.

[EGD-6882] Fix call hangup after BT device disconnect

Updated the BT stack with events that are handled through the
button so now it's possible to fallback to the earspeaker when
BT connection is lost

Added handling of those events

Merge branch 'stable'

[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

[EGD-2949] Fix fallback image

Added fallback image in case
of missing image asset

[EGD-6702] Add time zone library

The library is used to manually set the time zone.
It is based on the IANA time zone database.