feat: CountingSort implementation

[alxkm]

CountingSort implementation.

Previous discussion in this PR
#5275

• 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 40.50%. Comparing base (87e6184) to head (db9be2b).

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #5287      +/-   ##
============================================
+ Coverage     40.41%   40.50%   +0.09%     
- Complexity     2485     2494       +9     
============================================
  Files           518      519       +1     
  Lines         15451    15470      +19     
  Branches       2948     2950       +2     
============================================
+ Hits           6244     6266      +22     
+ Misses         8916     8915       -1     
+ Partials        291      289       -2     

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