Optimize D* Lite with heapq for O(log n) performance

[TahaZahid05]

Reference issue

Fixes #1333

What does this implement/fix?

This PR optimizes the D* Lite algorithm by replacing the list-based priority queue with a heapq-based implementation using lazy deletion.

Performance improvements:

• Priority queue operations: O(n log n) → O(log n)
• Node lookup: O(n) → O(1)

Changes:

• Implement min-heap priority queue using heapq
• Add lazy deletion pattern with entry_finder dictionary
• Add __eq__ and __hash__ methods to Node class for proper dictionary operations
• Add comprehensive docstrings to new priority queue methods
• Update unit tests to verify path finding with dynamic obstacles

Compatibility:

• Uses only standard library (heapq) - no new dependencies
• Maintains identical algorithm behavior and visualization
• All existing functionality preserved

Additional information

The optimization significantly improves scalability for larger grids and scenarios with frequent obstacle updates, while maintaining the exact same algorithm behavior and API.

CheckList

• Did you add an unittest for your new example or defect fix?
• Did you add documents for your new example?
• All CIs are green? (You can check it after submitting)