[EGD-5390] Add keypad backlight to GUI

Added demo connection to keypad light
GUI window.

[EGD-3247] Remove reminders of unused ping-pong feature

Feature was already removed some time ago but still some reminders
persist. This commit only removed mentioned reminders.
Some minor style fixes suggested by clang tidy were also applied.

[EGD-4831] Add license headers to c, h and sql files

Add license headers to `h`, `c` and `sql` files as this files haven't
been checked previously, script now to automatically updates current
year in existing licenses.

Merge branch 'master' into stable

[EDG-4717] Add screen for brightness control

Window for manual and automatic screen brightness control.

Merge commit 'c7dd6b399' into stable

Merge branch 'master' into stable

[EGD-2501] Add gsm powerdown due to battery

Gsm model power state maintenance based on battery level.

[EGD-4737] Add VoLTE ON/OFF switch in Settings Network window

Add VoLTE ON/OFF switch in Settings Network window

[EGD-4628] Add APN settings and URC handler for PDP context

Classes supporting APN settings on modem and telephone
configuration (synchronization) have been constructed.
Possibility of asynchronous execution
of individual actions via ServiceCellularAPI.
Added message with information about deactivation of the
PDP context (URC) that the
application / service can listen on.

[EGD-5050] Add brownout detection

Brownout detectection realized through charger driver

[EGD-4978] Add Bluetooth virtual audio device

Bluetooth audio device requires different handling than other
audio devices. The commit adds proxy device that does not
handle requests itself but instead sends requests too Bluetooth
service.

[EGD-4952] Added critical level check + messages

Merge branch 'master' into stable

[EGD 4654] spike light sensor to display (#1158)

* [EGD-4654] Light control first working

* [EGD-4654] Extended interface with custom brightness function

* [EGD-4654] Extended set of actions

* [EGD-4654] Fixed timer issue + cleanup

* [EGD-4654] Improving switch-case logic

* [EGD-4654] Moved keypad light control to previous state

* [EGD-4654] Refactor in screen light message

* [EGD-4654] Documentation work

* [EGD-4654] Extension of docu

* [EGD-4654] Typo fixing

* [EGD-4654] More improvements in doc

* [EGD-4654] Doxy generation fixes

* [EGD-4654] Pre pr cleanup

* [EGD-4654] PR comments pt 1

* [EGD-4654] Docu small change

* [EGD-4654] Doc updated with pumls

* [EGD-4654] added newlines at the end

Co-authored-by: Wojtek Rzepecki <wojtek.rzepecki@mudita.com>

Merge branch 'master' into stable

[EGD-4009] alarm clock: add main window (#1100)

Create alarm clock application and add main window.

[EGD-4653] BSP: amblient light sensor (#1135)

* [EGD-4653] Added first working readout

* [EGD-4653] Light sensor first working irq

* [EGD-4653] Interrupt config

* [EGD-4653] Cleanup

* [EGD-4653] Linux target file added

* [EGD-4653] Added messages with readout + fix of keypad light message

* [EGD-4653] Proper lux calculation

* [EGD-4653] Branch fix

* [EGD-4653] Pre PR cleanup

* [EGD-4653] Clang tidy hints application

* [EGD-4653] PR comments pt1

* [EGD-4653] Style branch fix

* [EGD-4653] Pr comments pt2

Co-authored-by: Wojtek Rzepecki <wojtek.rzepecki@mudita.com>

Merge branch 'master' into stable

[EGD 4449] display backlight (#1120)

* [EGD-4449] Added fsl drivers for pwm

* [EGD-4449] Added sketch of cpp wrapper for PWM driver

* [EGD-4449] First configuration of pwm

* [EGD-4449] Pin Mux config added

* [EGD-4449] Finalized basic configuration

* [EGD-4449] Added layer of eink frontlight control

* [EGD-4449] Added to worker event

* [EGD-4449] Added getter for brightness level

* [EGD-4449] Added mutex and clamp

* [EGD-4449] First working PWM driver configuration

* [EGD-4449] More minimalistic interface

* [EGD-4449] Cleaning and refactoring

* [EGD-4449] Connected to message system

* [EGD-4449] Added gamma correction

* [EGD-4449] PWM Start/Stop logic configuration

* [EGD-4449] Linux target file added

* [EGD-4449] Minor refactorings

* [EGD-4449] Branch style fix

* [EGD-4449] PR comments pt 1

* [EGD-4449] PR comments pt 2

* [EGD-4449] branch style fix

* [EGD-4449] PR pt3 - messages change

* [EGD-4449] Minor change

* [EGD-4449] BrightnessLevel type added

* [EGD-4449] Moved processing to EventManager

* [EGD-4449] 1-5 levels to percentage

* [EGD-4449] Fix style

Co-authored-by: Wojtek Rzepecki <wojtek.rzepecki@mudita.com>