[EGD-6315] Fix issues during saving new APN

- disallow saving empty APN form - at least `Name` must be provided,
- show `Save` button only if `Name` field is not empty,
- return to APN list window after adding/editing/deleting APN
  or setting APN to default

[EGD-6064] Add connecting and pairing bluetooth states

Pairing and connecting states are now visualized
in All devices window to inform phone user what is happening.

[EGD-6613] Audio assets tags are not displayed

When selecting ring/sms/notification sound the title from audio tags is
displayed. If tags are empty the filename is shown.

[EGD-6452] Sound selection GUI

Sound selection GUI used to change ringtone, message sound and
notification sound in settings.

[EGD-6301] Add Connecting to the network in intervals

It implements mode Offline Messages only - connecting to
the GSM network in defined by user intervals and rejecting
incomig calls during connected phase. It also implements
handling of connetion interval setiing and small fix in modes
popup.

[EGD-5773] Device becomes not responsive when opening settings

Use asynchronous communication with service cellular
to obtain own number.

[EGD-6527] Internationalization API unification

Single api to rule i18n
all calls to localistaion in cpp files unified
cut off ass many dependencies in i18n header as possible

[EGD-6485] Remove Cellular message types from global

Domain-specific message types should not pollute global space.

[EGD-6575] Rename Unicast with timeout as UnicastSync

Using Unicast with timeout is dangerous and strongly discouraged.
This change allows for more precise tracking of such cases.

[EGD-6555] ListView constants move

ListView constants moved from style to ListView.hpp.

[EGD-6552] Options cleanups and fixes

Fixed options crashes and cleared its structure. All
options returns points to proper list indexes.

[EGD-6093] Audio settings API

Refactored Audio settings API.
Moved phone modes logic from serivce audio to service clients level.
Removed redundant API.
Seprated API for vibration and sound enable/disable.
Fixed issues with vibrations logic.

[EGD-6505] Implement “On when active” Keypad light functionality

Implement “On when active” Keypad light functionality

[EGD-5440] Onboarding passcode window

Add windows for setting passcode during onboarding process

[EGD-6494] Application Manager on action switch fix

Application Manager switch on Action no longer causes to
newly opened application main window switch but it
calls declared action handler.

[EGD-6347] Refactored phone modes handling in applications

PhoneModeObserver doesn't work properly in applications.
Applications have to handle the phone mode changes via AppMgr.
Phone mode and tethering handlers separated.

[EGD-6208] Add blocking phone mode changes during tethering

When the tethering is enabled, the phone mode shouldn't change,
now, any attempt ends with a notification

[EGD-6433] Implement SIM PIN enable request

Implement SIM PIN enable/disable request
in PinLockHandler

[EGD-4736] Change PIN windows

Implement changing SIM PIN code flow

[EGD-6209] Tethering confirmation popup added

Provided a tethering confirmation popup.
The popup shows up once a USB cable is connected to a PC.