refactor: Add error handling and optimize marker/camera operations

[berhili098]

This pull request primarily focuses on enhancing error handling and code organization in the example/lib/pages/camera.dart and example/lib/pages/markers.dart files. The most important changes include adding try-catch blocks for error handling, refactoring camera movement logic into a helper method, and improving marker management.

Error Handling Enhancements:

• Added try-catch blocks to the _startNavigation, _stopNavigation, dispose, and calculateFocusCenter methods to handle potential errors and display appropriate messages. [1] [2] [3]
• Introduced error handling in marker management methods such as addMarkerToMap, _removeMarker, clearMarkers, _updateSelectedMarkerWithOptions, _toggleCustomIcon, and dispose to ensure robust error messages are shown. [1] [2]

Code Organization Improvements:

• Refactored camera movement logic into a new helper method _moveCameraWithAnimation to reduce code duplication and improve readability. [1] [2] [3] [4] [5] [6] [7] [8]
• Consolidated marker property updates into a single helper method _updateMarkerProperty to streamline the code and reduce redundancy.

These changes collectively enhance the robustness and maintainability of the codebase.

• Tests pass
• Appropriate changes to documentation are included in the PR