Added Bellman-Ford algorithm implementation in Java

[InbarAbraham]

• Added the Bellman-Ford algorithm implementation in Java.
• The code follows the Java naming conventions and is formatted according to the contributing guidelines.
• The algorithm calculates the shortest path and detects negative weight cycles in a graph.

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 73.84%. Comparing base (0e0539e) to head (8f18c13).
Report is 1 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #6147      +/-   ##
============================================
+ Coverage     73.83%   73.84%   +0.01%     
  Complexity     5156     5156              
============================================
  Files           661      661              
  Lines         17687    17687              
  Branches       3409     3409              
============================================
+ Hits          13059    13061       +2     
+ Misses         4120     4119       -1     
+ Partials        508      507       -1     

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[siriak]

It's already implemented at src/main/java/com/thealgorithms/datastructures/graphs/BellmanFord.java