Feature: Favorites, Recent activities, action bar hides on scroll

[butzist]

📋 Pull Request Checklist

• I confirm that this code is written and documented in English.

  English ensures global understanding, collaboration, and maintainability.

• I thoroughly tested this code on the following Android device(s):

  • Device model(s): Pixel 6, Samsung Galaxy XCover 5
  • Android version(s): 14, 16
  • Emulator or physical device: real
  • Screen size/resolution (if relevant):

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• I have linked related issues (if applicable).

🔍 Description of the Changes

• Added favorites list
• Added recent activities list
• Action bar layout hides search and action bar on scroll
• ViewModels for all Fragments to allow screen rotation without losing context

🔗 Related Issues

• [FEATURE] A tab/screen within the app for Favorites #456
• Add an option to directly launch an activity instead of opening the menu #373
• Going back clears the search box #251

🤝 Respect & Responsibility

By submitting this pull request, I agree to maintain a respectful and
collaborative tone. I acknowledge that contributing to open source is a team
effort.