[EGD-6214] Add slider position reading after disabling tethering

To be able to set proper phone mode changed by the slider during
tethering, the forced readout of slider position has been added

[EGD-6416] Add handling of headset keys

Change the volume level using headset keys

[EGD-5748] Revert remake cellular flow

Reverts changes due to reported issues

[EGD-5748] Remake Cellular flow

This commit changes TS0710 Worker operation.
1. It introduces MessageBuffers as main
interprocess data passing mechanism.
2. DMA transaction status codes and CMUX errors
are now propagated to Service.
3. Data processing has been refactored.

[EGD-6101] Add low battery start prevention

Device will be shutdown after
startup if SOC will be below
shutdown level

[EGD-5969] Add battery charging UI

Battery charging UI modified
according to design

[EGD-5660] Add PWM Cpu sentinel

Change of PWM frequency due
to main clock change in low
power operation.

[EGD-5737] Merge master into experimental

Synchronize with master before merging

[EGD-5312] Add Time selection window

- add ChangeDateAndTimeWindow,
- extract EventTimeItem to common widgets folder
  and rename it to TimeWidget,
- extract EventDateItem to common widgets folder
  and rename it to DateWidget,
- replace timeWidget with common TimeWidget
  in NightshiftWindow,
- refactor time setting in
  DesktopMainWindow and TopBar,
- Remove dead code from EventManager
  (GetNextAlarmTimestamp and HandleAlarmTrigger)

[EGD-3685] Vibra handling

Added driver & business logic. Responds to messages.

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5737] Merge master into experimental

Keep experimental up to date with changes from master

[EGD-5028] Add batt critical level db

Battery critical level sotred in
database.

[EGD-4797] Battery bar as widget

Battery bar now is present as
a separate widget in top bar.
Additionally refactored passing
battery status.

[EGD-5577] Add charger temperature cutoff

Battery charger cutoff due in
selected temperature range. Proper
charged state detection for rt1051

[EGD-5158] Change access to the bus methods

The bus is now accessible only via Service object.

[EGD-5575] Add battery file test

Battery file existence test for
harness test suit. Minor changes to
file saving applied.