Implement compression and decompression for Huffman coding

[mashraf8]

This PR introduces two new methods, compress_encoded and decompress_encoded, to improve Huffman encoding efficiency. The problem stems from that encoded binary strings are often long to store or transmit efficiently.

The compress_encoded method ensures that an encoded binary string is padded to a multiple of 8 and then converts every 8-bit chunk into a single character. The decompress_encoded method reverses this process by converting characters back into their corresponding binary representation and removing the added padding.

These changes enhance storage efficiency while maintaining lossless reconstruction of the original data. Doctests confirm the correctness of the implementation, ensuring that encoding, compression, decompression, and decoding operations preserve the original input.

📝 Checklist

• The title is concise and informative.
• The description explains in detail what this PR is about.
• I have created tests covering the changes.
• I have updated the documentation and checked the documentation preview.