✨ feat: Add loading container for lighthouse scanning

[Zaphkiel-Ivanovna]

📚 Context

This PR improves the user experience by adding a loading component to display during the lighthouse scanning process.

✍️ Description

• Added _buildLoadingComponent to show a CircularProgressIndicator, an icon, and helpful messages.
• Updated the FutureBuilder to display the loading component while scanning.
• Replaced the empty container previously used with the new loading UI.
• Used ThemeData and Theming to ensure consistent styling.

🧪 Testing

1. Navigate to the main page.
2. Start scanning and confirm the loading UI is displayed.
3. Verify fallback content appears if no lighthouses are found.
4. Test responsiveness across different devices and themes.

ScreenRecording_01-27-2025.20-48-26_1.MP4

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 61.06%. Comparing base (54394cf) to head (dcd0638).
Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #304   +/-   ##
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  Coverage   61.06%   61.06%           
=======================================
  Files          35       35           
  Lines        1261     1261           
=======================================
  Hits          770      770           
  Misses        491      491           

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[jeroen1602]

Thanks for this contribution!