Replace http_parser.rb with llhttp or other equivalents

[ashie]

Describe the bug Fluentd depends on http_parser.rb but it's not maintained and not released new version since December 11, 2013. In this gem, vulnerability is often detected mistakenly by several security tools because it includes a garbage Gemfile.lock. e.g.) #3409 #3374

I'm troublesome to support such issue, so that I've gotten ownership of http_parser.rb and I'll release a new gem which fixes this issue. Although such false positive will be suppressed by it, we should consider replacing http_parser.rb with other equivalents such as llhttp because dependent http-parser is already dead too.

To Reproduce See https://github.com/nodejs/http-parser

http-parser is not actively maintained. New projects and projects looking to migrate should consider llhttp.

Expected behavior Dependent libraries should be well maintained.

Your Environment N/A

Your Configuration N/A

Your Error Log N/A

Additional context N/A