feat(datastructures): add SelfOrganizingLinkedList implementation and tests

[iamcodinghere22]

This PR implements the Self-Organizing Linked List data structure using the "Move To Front(MTF)" heuristic.
In this implementation, whenever an element is accessed/searched, it is dynamically moved to the head of the list. This optimizes access time for frequently requested items by keeping them near the front, achieving an {O(1)} best-case lookup time for repeated accesses.

Changes Included

• Added SelfOrganizingLinkedList.java under com.thealgorithms.datastructures.lists.
• Added comprehensive unit test coverage in SelfOrganizingLinkedListTest.java verifying search, insertion, edge cases (empty list, non-existent elements), and move-to-front behavior.

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Testing

• All unit tests in SelfOrganizingLinkedListTest.java pass locally (mvn test -Dtest=SelfOrganizingLinkedListTest).
• Verified full build and test suite run successfully with JaCoCo code coverage.

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Checklist

• Code follows project coding guidelines.
• Unit tests have been added for new functionality.
• No duplicate code or classes introduced.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 94.28571% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.61%. Comparing base (56e2699) to head (67df287).

Files with missing lines	Patch %	Lines
...datastructures/lists/SelfOrganizingLinkedList.java	94.28%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #7575      +/-   ##
============================================
+ Coverage     80.59%   80.61%   +0.01%     
- Complexity     7483     7495      +12     
============================================
  Files           815      816       +1     
  Lines         24060    24095      +35     
  Branches       4736     4741       +5     
============================================
+ Hits          19390    19423      +33     
- Misses         3907     3909       +2     
  Partials        763      763              

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[iamcodinghere22]

Hi @DenizAltunkapan @yanglbme @alxkm,
All checks have passed successfully and the branch is ready.
Could one of you please review and approve this PR so it can be merged?
Thanks

[DenizAltunkapan]

Nice addition, a self-organizing list with move-to-front is a good fit here and there's no existing one. The algorithm itself looks correct. A few things to sort out before this can go in, left inline.

[DenizAltunkapan]

Calling the node class LinkedList is confusing, it's a node, not a list, and it clashes with java.util.LinkedList. The repo already has a convention for this (SinglyLinkedListNode). Could you rename it to Node and make it a static nested class inside SelfOrganizingLinkedList? That also keeps it to one top-level class per file, which is what the other list files do.

[DenizAltunkapan]

Codecov flags two uncovered lines, these getters (getSize / isEmpty) look like the culprits. Worth a small test so the patch is fully covered.

[DenizAltunkapan]

The tests only check getHeadValue, so they confirm the searched element ends up at the front but never that the rest of the list survives. A broken move-to-front (lost node, cycle, wrong order) would still pass all of these. Could you add a test that walks the whole list after a search and asserts the full order plus unchanged size? A duplicate-value case would be good too.