Add Onboarding Screen for Improved User Experience

[teogor]

In this pull request, we introduce an Onboarding Screen to enhance the user experience and provide important information about the app's functionality. The Onboarding Screen is a crucial step for new users and helps them understand the app's features and permissions.

Changes Made:

1. Added a new package dev.teogor.ceres.screen.ui.onboarding to contain the Onboarding Screen components.
2. Introduced OnboardingRoute as a new screen route for the Onboarding Screen.
3. Created the OnboardingScreenData class to store data related to the Onboarding Screen, including app name, description, permissions, privacy policy link, terms of service link, and permission categories.
4. Added Permission, PermissionCategory, PrivacyPolicy, and TermsOfService classes to handle permissions and legal information.
5. Created enum OnboardingScreen to represent different Onboarding Screen sections.
6. Implemented individual screens for the Onboarding Screen, including IntroScreen, LegalScreen, AdChoicesScreen, and PermissionScreen.
7. Added navigation paths for the Onboarding Screen using NavGraphBuilder.
8. Modified the NavHost to determine the start destination based on whether the Onboarding Screen is complete and if consent to show ads is granted.
9. Updated the navigation logic to include the Onboarding Screen as part of the user onboarding process.

closes #125