Add GoogleKCParser implementation with tests and CLI script

[dkallipo]

This PR adds the complete implementation for the GoogleKCParser, including:

• lib/google_kc_parser.rb: Main parser logic.
• bin/run_parser.rb: CLI script to run the parser on a given HTML file.
• test/test_parser.rb: Automated tests using Test::Unit with multiple scenarios.
• Sample HTML input files and matching expected JSON output files.

Usage

Run parser from CLI:
ruby bin/run_parser.rb <html_file>

Run tests:
ruby test/test_parser.rb

Note: In expected JSON files, the order of results matters.

Tested on Ruby 2.6.5, should work on any Ruby 2.5+ environment.