Fix incorrect RFC 4648 section references:
- Add RFC URL reference at package level
- Update Error enum documentation to reference correct sections:
- Invalid_Character: Section 3.3 (non-alphabet characters)
- Invalid_Length: Section 6 (base32 block size requirements)
- Malformed_Input: Section 3.2 (padding)
- Fix test file section references to match correct sections
This ensures all RFC references are accurate and adds a link to the
source RFC for reference.
Add defer delete for encoded strings across all test procedures to ensure
proper cleanup and prevent memory leaks. This completes the memory
management improvements started in 591dd876.
Add test case to verify custom alphabet support. The test uses a
decimal-uppercase alphabet (0-9, A-V) to test both encoding and decoding
with custom tables, including validation. This ensures the encode and
decode functions work correctly with custom encoding tables and
validation functions as documented.
Add test_base32_roundtrip() to verify the encode->decode roundtrip
preserves data integrity. This test helps ensure our base32 implementation
correctly handles the full encode->decode cycle without data loss or
corruption.
