add ZAlgorithm for linear pattern matching

[Roniscend]

Description

Implements the Z-Algorithm for pattern matching in linear time O(n+m).

Changes

• Added ZAlgorithm.java with linear time pattern matching implementation
• Added comprehensive test cases in ZAlgorithmTest.java
• Includes both pattern search and Z-array computation methods

Features

• O(n+m) time complexity for pattern matching

• Handles edge cases (null inputs, empty strings, overlapping patterns)

• Well-documented with JavaDoc comments

• 13 comprehensive test cases covering all scenarios

• [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

❌ Patch coverage is 0% with 35 lines in your changes missing coverage. Please review.
✅ Project coverage is 75.10%. Comparing base (5e9d9f7) to head (095fa07).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
...ain/java/com/thealgorithms/strings/ZAlgorithm.java	0.00%	35 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##             master    #6579      +/-   ##
============================================
- Coverage     75.23%   75.10%   -0.13%     
- Complexity     5626     5629       +3     
============================================
  Files           691      692       +1     
  Lines         19448    19485      +37     
  Branches       3758     3768      +10     
============================================
+ Hits          14632    14635       +3     
- Misses         4248     4283      +35     
+ Partials        568      567       -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.