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.
Added Dialog windows for "configuration successful"
"no configuration" and "update OS" for Onboarding.
Refactor Dialog window implementation and usage of
DialogMetadata in other applications.
