Refactor: Update project name and package structure

This commit updates the project name from "Call Budy" to "Jetpack Boilerplate".

Key changes include:
- Updated application ID, namespace, and theme names.
- Renamed relevant packages and files.
- Added Hilt for dependency injection and created `MyApplication`.
- Implemented basic navigation between `HomeScreen` and a new `DetailsScreen`.
- Added `HomeScreenViewModel` and `DetailScreenViewModel`.
- Updated Gradle dependencies and configuration files.
- Added snapshot repository for androidx artifacts.