[ty_test] Use named fields for UnparsedAssertion::Hover
Convert the Hover variant from tuple-style to named fields for better
clarity and self-documentation.
Before: Hover(&'a str, &'a str, TextRange)
After: Hover { expected_type, full_comment, range }
This makes the code more readable and easier to maintain.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
