[BH-765] Turn off the device

From now on, Bell can be switched off from:
- settings
- by back long press(5s) from any screen

[BH-925] Replace placeholder icons with final ones

Replace placeholder icons with final ones.
Replace old bad icons with a new good one.

[EGD-7631] PhoneLock timer system time independence refactor

Refactored PhoneLock to be independent of system time.
Refactored refresh options for notification receive on
Windows.

[BH-852] Bell settings language selector

Bell settings language selector.

[BH-865] About screen in Settings

Implement AboutYourBellWindow.

[BH-702] Bell OnBoarding welcome window added

Bell OnBoarding welcome window added.

[BH-922] Fix alarm activate popup

Fix activate popup to have proper alarm time
Change activate/deactivate popup to use alarm model

[BH-921] Fix missing alarm set windows

Fix missing alarm set windows
Fix wrong alarm time description format
Fix wrong alarm disable icon

[BH-758] Alarm tone, volume & light

Implement "Alarm tone, volume & light" settings flow.

[BH-670] Wake up greeting

Added random wake up greeting text.

[BH-893] Add BGSounds progress window

The commit provides an implementation to MVP of
BackgroundsSounds ProgressWindow. The implementation
is restricted to basic UI and timer functionality.

[BH-884] Add Timer value selection window

The commit implements MVP for BackgroundSound's Timer
window. In order to print string values (e.g. OFF)
the Timer is relised by UTF8Spinner.

[BH-823] Pre-wake up settings - part II

Implement Pre-wake up settings logic.

[EGD-7612] Add alarm popup

Added alarm popup window. Added ImageBoxWithText
widget.

[EGD-7310] Alarm GUI and features update

Updated AlarmOptionsItem to use UTF8Spinner.
Created specialized widgets to cover options
sets. Updated GenericSpinner to handle Pure
navigation and content swap. Updated Alarm
RRule code to work with Custom Days selection
and new widgets. Added Tests. General GUI
stylistic fixes. Increased app Alarm Clock
and service Time stack sizes.

[BH-703] Base Bell OnBoarding application

Added base Bell OnBoarding application. Bell list
options refactor.Language selection, setting and
finalize windows.

[EGD-7569] Add Alarm snooze list notification

Notification added to notifications model

[BH-862] Snooze settings

Added snooze settings flow.

[EGD-7409] Empty list additions and fixes

Fixed bug in empty lists displays and added missing
empty lists in applications.

[BH-850] PowerNap: SessionEnd implementation

The implementation of the SessionEnd covers:
* SessionEnd window
* SessionEnd Presenter

Additionaly in order to match application's flow requirement
the PowerNapProgress was equipped with:
* OnInput behaviour that allows to transition to the
SessionEnd window
* AlarmTimer timer that automatically transitions to
the SessionEnd window