feat: add IndexedPriorityQueue implementation and tests

[SeungHyeokYoon]

• 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

❌ Patch coverage is 97.52066% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.45%. Comparing base (c6880c1) to head (d312dad).

Files with missing lines	Patch %	Lines
...hms/datastructures/heaps/IndexedPriorityQueue.java	97.52%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #7062      +/-   ##
============================================
+ Coverage     78.35%   78.45%   +0.09%     
- Complexity     6689     6730      +41     
============================================
  Files           756      757       +1     
  Lines         22203    22324     +121     
  Branches       4365     4382      +17     
============================================
+ Hits          17398    17514     +116     
- Misses         4106     4108       +2     
- Partials        699      702       +3     

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[SeungHyeokYoon]

I had a simple idea and implemented it as this IndexedPriorityQueue. I’d appreciate it if you could kindly take a look :)