feat: Improve accuracy of polyline click, and refactor variable naming and eliminate duplicate functions in core module.

[wf9a5m75]

Summary

Improve: the accuracy of polyline click detection especially on the geodesic polyline.
Uses GeographicLib for better calculation.

Screen_recording_20251005_111827.webm

Refactor: Improve variable naming and eliminate duplicate functions in core module
This PR improves code readability and maintainability by refactoring variable names and eliminating duplicate functions in the core module. The changes focus on making the codebase more self-documenting and reducing code duplication.

Changes Made

1. Single Character Variable Renaming
2. Short Ambiguous Variable Renaming
3. Function Deduplication

Eliminated duplicate utility functions and improved naming:

• Distance calculation: Removed haversineDistance() function and unified usage to
  Spherical.computeDistanceBetween()
• Longitude normalization: Removed private Spherical.normalizeLng() and standardized on Utils.normalizeLng()
• Function renaming: Spherical.interpolate() → Spherical.sphericalInterpolate() for clarity

Benefits

• Improved readability: Variable names now clearly indicate their purpose
• Reduced maintenance burden: Eliminated duplicate code reduces the risk of inconsistencies
• Better self-documentation: Code is more understandable without additional comments
• Clearer API: Function names better reflect their specific algorithms (e.g., spherical vs linear interpolation)

Testing

• All existing functionality remains unchanged
• Lint checks pass successfully
• No breaking changes to public APIs