Add unit tests for graph algorithms (#7133)

[LucasAHorn]

This PR builds on the work by @prashantdubeypng in PR #7152 and adds missing unit tests for graph algorithms, addressing issue #7133:

• BellmanFordTest.java: 10 test methods covering various graph scenarios, including negative edge weights and disconnected graphs.
• ConnectedComponentTest.java: 15 test methods for DFS-based component counting in different graph structures.
• MatrixGraphsTest.java: additional BFS/DFS test cases to verify traversal correctness.
• DijkstraAlgorithmTest.java: comprehensive shortest path tests for weighted graphs.

This PR also applies proper clang-format formatting to ensure all CI checks pass.

Fixes #7133

Checklist:

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized it.
• All filenames are in PascalCase.
• All functions and variable names follow Java naming conventions.
• All new algorithms have a URL in their comments that points to Wikipedia or other similar explanations.
• All new code is formatted with clang-format -i --style=file path/to/your/file.java

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.87%. Comparing base (520151a) to head (8ae0f94).

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #7156      +/-   ##
============================================
+ Coverage     78.63%   78.87%   +0.24%     
- Complexity     6825     6828       +3     
============================================
  Files           766      766              
  Lines         22607    22607              
  Branches       4444     4444              
============================================
+ Hits          17776    17831      +55     
+ Misses         4118     4064      -54     
+ Partials        713      712       -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[DenizAltunkapan]

@LucasAHorn Thank you for your contribution