Add GCD implementation using Euclidean algorithm

[Swati89923]

Added a GCD implementation using the Euclidean algorithm along with unit tests.

• 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 similar explanations.
• All new algorithms include a corresponding test class that validates their functionality.
• All new code is formatted according to the project standards.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.92%. Comparing base (e945f16) to head (132dbd6).

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #7189      +/-   ##
============================================
+ Coverage     78.91%   78.92%   +0.01%     
- Complexity     6883     6886       +3     
============================================
  Files           774      775       +1     
  Lines         22746    22758      +12     
  Branches       4468     4471       +3     
============================================
+ Hits          17949    17962      +13     
+ Misses         4077     4076       -1     
  Partials        720      720              

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[Swati89923]

Hi maintainers 👋
Just checking in. Please let me know if any changes are needed from my side.
Thanks!

[Swati89923]

Hi maintainers 👋
Just checking in. Please let me know if any changes are needed from my side.
Thanks!

[DenizAltunkapan]

@Swati89923 whats the difference between your implementation and https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/maths/GCD.java ?

[github-actions]

This pull request has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contribution!