feat: solve 49. Group Anagrams with unit testing

[mathusanm6]

closes #80

[Copilot]

Pull Request Overview

This PR implements a solution for LeetCode problem 49 "Group Anagrams" with comprehensive unit testing support. The implementation provides solutions in both Python and C++ languages with different algorithmic approaches.

• Adds Python solution using character frequency counting (O(n*k) time complexity)
• Adds C++ solution using string sorting approach (O(n*k log k) time complexity)
• Includes comprehensive unit tests for both implementations with edge cases

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
problems/group_anagrams/group_anagrams.py	Python implementation using character frequency counting to group anagrams
problems/group_anagrams/group_anagrams.cc	C++ implementation using sorted strings as keys to group anagrams
problems/group_anagrams/group_anagrams.h	C++ header file declaring the groupAnagrams function
problems/group_anagrams/group_anagrams_test.py	Python unit tests with parameterized test cases covering edge cases
problems/group_anagrams/group_anagrams_test.cc	C++ unit tests using Google Test framework with comprehensive test cases
problems/group_anagrams/config.yml	Configuration file with problem metadata and complexity analysis
README.md	Updates solution count badges and adds entry to the problems table

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