refactor: Enhance docs, add tests in `HashMapCuckooHashing`

[Hardvan]

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

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 60.00000% with 4 lines in your changes missing coverage. Please review.

Project coverage is 71.20%. Comparing base (84cd883) to head (f19399e).

Files with missing lines	Patch %	Lines
...ructures/hashmap/hashing/HashMapCuckooHashing.java	60.00%	3 Missing and 1 partial :warning:

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #5975      +/-   ##
============================================
+ Coverage     71.15%   71.20%   +0.05%     
- Complexity     4890     4893       +3     
============================================
  Files           650      650              
  Lines         17529    17526       -3     
  Branches       3378     3376       -2     
============================================
+ Hits          12472    12479       +7     
+ Misses         4587     4580       -7     
+ Partials        470      467       -3     

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.