This PR modernizes SRS's HTTP handling by upgrading from the legacy
http-parser library to the more performant and actively maintained
llhttp library.
* Replace http-parser with llhttp: Migrated from the deprecated
http-parser to llhttp for better performance and maintenance
* API compatibility: Updated all HTTP parsing logic to use llhttp APIs
while maintaining backward compatibility
* Simplified URL parsing: Replaced complex http-parser URL parsing with
custom simple parser implementation
Enhanced error handling: Improved error reporting with llhttp's better
error context and positioning
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Co-authored-by: OSSRS-AI <winlinam@gmail.com>
