Add Quick Sort algorithm

Closes #2 (closed) - Add Quick Sort algorithm

Implemented Quick Sort algorithm with the following features:

• Time complexity: O(n log n) average, O(n²) worst case
• Space complexity: O(log n)
• Uses median-of-three pivot selection to avoid worst-case on sorted arrays
• Follows project conventions for non-mutating sort functions

All 50 tests pass, including:

• Correctness tests on various input arrays
• Input mutation verification
• Algorithm metadata validation
• Performance test on 1000-element array