feat: support trailing dots in hostnames

[qjerome]

Summary
Support parsing URLs and domains containing a trailing dot in the hostname (e.g., http://shops.myshopify.com./). This addresses issue #18.

Motivation
URLs with trailing dots in hostnames are valid according to RFC standards but were previously rejected by the parser. This change enables proper parsing of such URLs while maintaining backward compatibility.

Changes

• Modified parser's grammar
• Added trim_end_matches(".") to strip trailing dots from hostnames during parsing
• Added test coverage for trailing dot scenarios

Breaking Changes
None

Testing

• Added test_url_trailing_dot() with multiple test cases
• All existing tests continue to pass
• Verified parsing of trailing dots with various URL components (path, query, fragment, port, userinfo)

Notes
The trailing dot is stripped during parsing but the original URL string remains unchanged in the orig field.