[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-5215] Add APNs list

Load APNs from service cellular.
Add ApnSettings model.
Connect ApnOptionWindow with ApnSettingsWindow.

[EGD-4960] registerVariableChange moved to Init section of apps

[EGD-5338] Add APN options window - gui

This is just GUI, window is not connected yet.
It will facilitate further development of APN settings,
and will be enhanced later.

[EGD-4995] Fix changing passcode windows

Some implementation of
"EGD-4995 Add changing passcode windows flow"
was removed from master by PR:
"EGD-4743 Add new/options windows to quotes".
This PR restores this implementation.

[EGD-4740] Add New/Edit APN window - Part1

Add New/Edit APN window - basic window/ model/ widget

[EGD-5288] Add Main system window

In settings add “System” window with all main menu items
(items are just menu positions not connected to actual windows)

[EDG-4743] Add new/options windows to quotes

Add windows for add/edit/delete quotes, use ListView for quote display.

[EDG-4717] Add screen for brightness control

Window for manual and automatic screen brightness control.

[EGD-4995] Add changing passcode windows flow

Implement changing passcode windows flow

Merge branch 'master' into stable

[EGD-4580] Add BT settings middleware

Added bluetooth settings middleware to store BT status in settings.
Added middleware layer to handle new settings queries.

[EGD-4739] Add empty APN settings window

APN settings window without APN list.
Icon widget now accepts rich text.

[EGD-5166] Add query-callback synchronization mechanism

Receiver object cancels the callbacks at the end of its lifecycle.

[EGD-4737] Add VoLTE ON/OFF switch in Settings Network window

Add VoLTE ON/OFF switch in Settings Network window

[EGD-4992] Add main Security screen

This commit implement only main Security screen.
Change passcode functionality will be implemented
in [EGD-4995].

[EGD-4869] Add bluetooth message status to application settings

This change demonstrates how to work with Bluetooth messages
in application settings windows.
Responses to bluetooth status messages are mocked because
settings storage and message handlers in Service Bluetooth
are not ready yet.

[EGD-4732] "All Operators" menu option is shown when "Operator auto-select" is off; the state is kept in db
[EGD-4732] Network menu items visibility / indentation