feat: add QuadTree datastructure

[sailok]

• 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

Attention: Patch coverage is 92.72727% with 4 lines in your changes missing coverage. Please review.

Project coverage is 63.62%. Comparing base (e38611e) to head (d130b19).

Files with missing lines	Patch %	Lines
...m/thealgorithms/datastructures/trees/QuadTree.java	92.72%	1 Missing and 3 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #5681      +/-   ##
============================================
+ Coverage     63.49%   63.62%   +0.12%     
- Complexity     4095     4109      +14     
============================================
  Files           575      576       +1     
  Lines         16083    16138      +55     
  Branches       3089     3100      +11     
============================================
+ Hits          10212    10267      +55     
+ Misses         5452     5451       -1     
- Partials        419      420       +1     

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[sailok]

@siriak will you able to take a look at this PR?

[siriak]

Looks good, thanks!