1. Prepare Pure and Bell specific `Application`
classes and add them to `app` target:
- `products/BellHybrid/apps/Application.cpp`
- `products/PurePhone/apps/Application.cpp`
2. Update `CMakeLists.txt` files.
3. Move `ApplicationBell` implementation to Bell-specific
`Application` class and remove `ApplicationBell` files.
4. Change Bell apps parent classes from `ApplicationBell`
to Bell-specific `Application` class.
5. Rename `Application` to `ApplicationCommon` in the rest of the files.
Finalized onBoarding application. Added no sim ready window
and sim response window. Created iceBox widget. Fixed various
onBoarding errors and misalignment.
Created first version of onBoarding application. Added welcome
window, configuration start window and adopted language
window. Small Icon GUI refactor. AppManager language copy removed.