enhance(perfomance): add rustworkx adapter implementation, benchmark suite, and unit tests

[dipanjannC]

Quantitative benchmark snapshot

Performance Comparison: NetworkX vs rustworkx

Graph Size	Build: NetworkX	Build: rustworkx	Build Ratio	BFS: NetworkX	BFS: rustworkx	Shortest Path: NetworkX	Shortest Path: rustworkx
1,000 nodes	17.46 ms	10.25 ms	1.70× faster	0.008 ms	0.026 ms	0.336 ms	0.384 ms
5,000 nodes	81.97 ms	63.09 ms	1.30× faster	0.007 ms	0.016 ms	0.309 ms	1.220 ms

Summary

• Graph construction: rustworkx is consistently faster (1.3×–1.7×)
• BFS traversal: NetworkX performs better in these cases
• Shortest path:
  • Comparable at smaller scale (1K nodes)
  • NetworkX significantly faster at 5K nodes

P.S. - Let me know if any changes you want to have.