[EGD-7779] Dark mode implemented

Experimental dark mode feature implemented.

[EGD-7799] Revert enable SSP authorised pairing

This reverts commit 649cacd1c3e61d813dbbd18e1d66413629353cbf as
the SSP was not working properly with all devices

[EGD-7852] Fix batteryr screens switch

fix of switch from dead/charging battery screens

[EGD-7738] Fix modem reset

Fixed modem reset procedur so now it will not stuck in cellular
init on factory fresh phone. Also removed T3/T4 board recognition.

[EGD-7766] Vibration level PWM addition

PWM channels separate control added.

[EGD-7766] Vibration level PWM addition

Added base PWM settings to vibrations. Added vibration
volume setting.

[BH-1012] Update frontlight settings app

Removed Home View from settings list(BH-1004)
Fixed default brightness value(BH-964)
Added missing Frontlight Mode view(BH-966)
Reworked frontlight settings app using NumListItems
and EvtMgr API to control screen backlight.
Fixed minor issues with side arrows and couple of minor
bugs.

[EGD-7666] Fix alarms time zones

update of the events cache every time change

[CP-610] Add removeFile operation to Filesystem EP

Moved Rename/Remove/ListDir from DeveloperMode to Filesystem EP API

[EGD-7798] Fix alarms backend with new format

New format of alarm time in database and processing

[EGD-7799] Enable SSP authorised pairing

This enables Simple Secure Pairing which is required to pair
from another device (device -> Pure). As for now, only KeyboardOnly
capabilities are enabled as we have all frontend and backend
already enabled for entering the pin code/passkey

[BH-943] Fix screen clean after exit

Remove cleaning screan after shutdown.

[BH-618] Power nap fixes

Implemented various fixes:
BH-995
BH-996
BH-997
BH-998
Fixed PlayActions
and more.

[BH-903] Pre-wake up frontlight

Implemented a frontlight handling for the pre-wake up.
Major clean-up of the frontlight implementation.

[EGD-7615] Fix Modem soft reset

Cellular is configuring modem after reset.

[BH-773] Add bedtime reminder application

Add bedtime time and on/off UI setup app
Add bedtime event notification window
Add bedtime audio assets
Implement bedtime notification TimeService backend
Add bedtime unittests

[EGD-7440] Fix BT statusbar after BT disconnect

BT statusbar was set by disconnect message, which was not
aware of BT on/off status, thus always after disconnect
the statusbar icon was set to idle/enabled

[EGD-7754] Dates bumped in disclaimers

Dates bumped from 2020 to 2021.

[CP-615] Update existing backup/restore implementation in OS

[CP-648] Handle updated API requests

Updated B&R to handle new API
Extended error reporting
Backup/Restore code clean up

[CP-649] Check OS version compatibility during restore
Added check of OS and backup versions
Fixed adding of version.json to PurePhone.img

[CP-599] Add crc hash to the last chunk of sent file

CRC was counted in one go before starting to send
chunks of the file, which, in the case of a large file,
caused communication to stop for a long while.
In the current implementation, CRC is counted
incrementally while sending individual file chunks.
It is then appended to the last chunk of the file.