[BH-1895][BH-1909][BH-1910] New database structure for custom sounds

* Added creation of /user/media/app/alarm
directory that will be used to store
custom alarm sounds.
* Implemented new database structure.
* Adapted Alarm, Bedtime, Pre-wake up and
Snooze to new database structure.
* Added removing custom alarm files during
factory reset.
* Added fallback alarm sound mechanism.
* Cleanups, unifications.

[BH-1898] Fix of GUI freeze after intensive volume change

Fix of the issue that GUI would freeze for
several seconds if volume level was being
changed intensively for a while.

[BH-1887] Speed up update process

* Added stream buffering for reading data
from tar archive with update.
* Increased size of the buffer used
for unpacking files from tar archive.
* Changed buffers data type from vectors
to raw heap-allocated arrays.

[BH-1815] Optimalize loading music files in relaxation

Add relaxation list refresh after files added or deleted

[BH-1688] Create a standard for logs

* Adding document describing how to use logger
* Adjusting logs to follow a new guide
* Change order in log header:
  line number is now before function name

[CP-1962] Add Harmony color detection

* Added serial number based Harmony color
detection.
* Unified serial number handling for both
products.

[MOS-856] Another approach to MTP path in DeviceInfo

This time it's device-agnostic from purefs paths

[MOS-856] Add MTP path to DeviceInfo endpoint

Added MTP path for products to enable MC to use it instead
of hardcoded paths

[MOS-807] Fix MTP root path

Fixed MTP root paths for both Harmony and
Pure due to the MTP implementation
not supporting hierarchical directories.

[MOS-807] Update scripts

Added update scripts for both variants:
UDM update and further 'normal' updates.

Minor updates to the directories layout

[MOS-803] Further fixes for sync

Fixed paths for sync process
Added timeout for windows in recovery processes

[MOS-803] DeviceInfo endpoint update

* Added some changes to the DeviceInfo endpoint
* Updated relevant code accordingly
* Removed unneeded paths definitions
* Minor bug fixes

[MOS-783] Change boot.bin to os.bin

Change the confusing system binary name.

[MOS-783] Fixed tests and simulator for Harmony

Fixed tests and simulator for Harmony
after implementation of new filesystem
structure.

[MOS-783] Moved battery config file to '/user/data'

Moved battery config file from root
directory of user partition to
'data' directory to comply with
new directory layout design.

[MOS-783] Fixed Pure unit tests

Fixed (most of the) hardcoded
paths in Pure's unit tests.

[MOS-783] Working Pure simulator after partition changes

Fixed iosyscalls so that Pure simulator
works after directory structure changes.

[MOS-786] Added A/B booting support in OS

Added basic support for A/B booting

[MOS-783] First part of new dir structure implementation

    Works:
    - generating .img for Pure;
    - Pure boots after flashing new image and
    seems to be working fine;

    Not yet:
    - generating update package;
    - generating image for Harmony;
    - simulator;
    - path-related unit tests fail
    due to paths being hardcoded
    in test scenarios.

[CP-1427] Cleanup leftovers after old backup restore implementation

The synchronization mechanism has been freed from the constraints
of the old backup and restore implementation.