feat: add CRC32 hash algorithm implementation

[rodrigobnogueira]

Description

Implements the CRC32 (Cyclic Redundancy Check 32-bit) hash algorithm, which is widely used for error detection and data integrity verification.

Changes

• Added hashes/crc32.py with complete implementation
• Uses IEEE 802.3 polynomial (0xEDB88320)
• Optimized with pre-calculated lookup table
• 17 comprehensive doctests including edge cases
• Cross-validated against Python's zlib.crc32()

Real-world Applications

• ZIP file format
• Ethernet frames
• PNG images
• GZIP compression
• Data integrity verification
• Error detection in network protocols

References

• https://en.wikipedia.org/wiki/Cyclic_redundancy_check
• https://www.rfc-editor.org/rfc/rfc1952

Testing

• All 17 doctests pass
• Passes ruff linting
• Passes mypy type checking
• Validated correctness against standard library zlib.crc32()

Checklist

• [x] I have read and followed the contributing guidelines
• [x] This pull request is not a duplicate
• [x] The algorithm is implemented from scratch
• [x] The code follows the repository style
• [x] I have read CONTRIBUTING.md
• [x] This pull request is all my own work -- I have not plagiarized
• [x] I know that pull requests will not be merged if they fail the automated tests
• [x] This PR only changes one algorithm file
• [x] All new Python files are placed inside an existing directory (hashes/)
• [x] All filenames are in all lowercase characters with no spaces or dashes
• [x] All functions and variable names follow Python naming conventions
• [x] All function parameters and return values are annotated with Python type hints
• [x] All functions have doctests that pass the automated testing
• [x] All new algorithms include at least one URL that points to Wikipedia or another similar explanation