[BH-1657][BH-1833][BH-1854] Add WFI and SDRAM self-refresh mode

* Added mechanism enabling CPU to
enter WFI mode when the OS is
in idle, what results in large
power consumption reduction.
* Added mechanism to switch SDRAM to
self-refresh mode before entering
WFI, what resulted in further power
consumption reduction.

[BH-1637] Add low battery screen before using the application

If the battery is discharged below 10%, the user gets a
notification before using the meditation and relaxation application.

[BH-1856] Add setting onboarding year to build year

Added mechanism automatically setting
the default year shown in the onboarding
to the year of build to avoid changing
it manually every year.

[BH-1635] Fix for low battery notification on the home screen

Fix for deep press blocked reaction.

[BH-1857] Fix improper PWM module clock frequency computation

* Fix of the issue that source clock for PWM
module was improperly assumed to be derived
from AHB_CLK, while in reality it is
derived from IPG_CLK, what resulted in
module generating signal with 4 times
lower frequency than the configured
one.
* Cleanups.

[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-1807] Fix missing AM/PM label in apps clock

* Fix of the issue that after changing font size
of the clock presented in Relaxation, Meditation
and Power Nap apps, AM/PM label was not shown
in 12h mode.
* Added logs informing about missing margins
map entry so that such issue is easier to debug
if it should happen in the future.

[BH-1731] Fix factory reset confirmation window layout

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

[BH-1845] Fixed time format in Settings and Onboarding (2)

This is the second fix. Now the time format in Settings and Onboarding is currently set
and changes dynamically during the user changing the time parameters.

[BH-1845] Fixed time format in Settings and Onboarding

Now the time format in Settings and Onboarding is currently set
and changes dynamically during the user changing the time parameters.

[BH-1836] Increase range of volume adjustment

Update default values

[BH-1807] Increase clock font

Increase clock font in Relaxation, Meditation, Power nap mode

[BH-1843] Add progress bar for volume adjustment windows

A progress bar has been added for all volume control windows.

[BH-1824] Removal of the minus sign in countdown time in Meditation

Removed minus sign in countdown timer in Meditation

[BH-1836] Increase range of volume adjustment

Extended volume scale from 10 to 15 point scale
Modified volume approximation function for better user experience

[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-1825] Remove minus sign in countdown timers of progress

Removed minus sign shown next to the remaining
time value for timers showing progress in
Meditation, Relaxation and Power Nap apps.
Style constants cleanup.

[BH-1826] Implement new countdown progress bar design

Implemented new countdown progress bar design,
used in Relaxation, Meditation and Power Nap
apps. New implementation shows progress
bar as decrementing as the time passes instead
of incrementing.
Cleanups.

[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-1838] Relaxation plays in the background for certain song lengths

Fixed problem with occasional background playback after song has finished