[BH-1635] Low battery notification on the home screen

A low battery warning window has been added to the main screen.
This notification will appear only once when the battery level falls to 15%.
It will also appear when the battery level falls below 10% and 5%.

[BH-1731] Fix factory reset confirmation window layout

* Fixed factory reset confirmation window
layout to match the corresponding design.
* Added missing translations.

[BH-1264] Add alarm sound fade in

Adding a fade in for the alarm sound (main and power nap) according to
the pattern (V): dt = 30[s] * V/10.

[BH-1731] Factory reset removes user files

Performing the factory reset removes user files
and settings. After powering on the device
will run the onboarding.

[BH-1795] Add noises to relaxation

Adding color of noises to Relaxation

[BH-1809][BH-1835] Add date format setting

Added date format selection between DD/MM and MM/DD.
The time setting has been updated.

[BH-1828] Add labels to relaxation sound list

Added labels to relaxation

[BH-1648] Add shortcuts instruction to settings

The user should be able to return to the shortcuts instruction at any
time. The instructions are available in the settings.

[MOS-1052] Change VoLTE label from 'beta' to 'experimental'

Changed VoLTE label from 'beta' to
'experimental'.
Fixed transition state label font
size to match the design.

[MOS-896] Update low battery screen view

Updated low battery screen view by adding
info windows appearing when trying to
interact with phone having critical
charge level.

[BH-1696] Notification when connect the device to the charger

Adding notifications when charger is connected

[MOS-669] Add too hot battery notification when charging

* Added notification showing on the main
screen if the battery has reached too
high temperature to continue charging.
* Code cleanups.

[MOS-1033] Add 'beta' label to VoLTE switch for selected countries

Added mechanism enabling to individually show
or hide "beta" label on VoLTE switch for each
country.

[MOS-1007] Fix for no popup when contact cannot be saved because of same nubers

Fix for fix. It add popup when user try to save contact witch practically
the same numners  (even if having a country code is only difference)

[MOS-1020] Fix for losing unsaved data

Fix for losing unsaved data when the user click the BACK button while
creating or editing note/contact.

[MOS-930] Change translations for Old Messages text

Change translations for Old Messages text to Previous Messages text.

[BH-1749] Fix diacritics in translations

Some texts did not have diacritics in the translations

[MOS-930] Fix for for misunderstanding holes in sms conversations

Not all messages can fit on the current screen in sms conversation windows,
so there may be some holes that might suggest that  there are no more messages
to display. Now, when therea are more SMS to see by scrolling up,
the Old Messages label will indicate this fact.

[MOS-1002] Change USSD code handling to match design

Fixed issues with GUI behaviour on failed
USSD code handling.
Minor code cleanup in several parts of system.

[BH-1733] Add Harmony version information

In the Settings->About section, we will have information
about which version of Harmony the user has.

co-author @Lefucjusz