Add unit tests for graph algorithms (#7133) (#7156)

* Add unit tests for graph algorithms (BFS, DFS, Dijkstra, Bellman-Ford) #7133

- Created BellmanFordTest.java with 10 test methods covering various graph scenarios

- Created ConnectedComponentTest.java with 15 test methods for DFS-based component counting

- Enhanced MatrixGraphsTest.java with additional BFS/DFS test cases

- Enhanced DijkstraAlgorithmTest.java with comprehensive shortest path tests

Fixes #7133

* fix: format files using clang

* fix: removing my changes on pull_request_template

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Co-authored-by: prashantdubeypng <vinoddubey6059@gmail.com>