feat: improve DOM parsing with accessibility tree

[devin-ai-integration[bot]]

Enhance DOM parsing logic by integrating Chrome's accessibility tree through Playwright's API.

Changes:

• Add accessibility utility module for semantic information retrieval
• Enhance element detection with accessibility tree information
• Improve visibility detection using accessibility properties
• Update interactive element detection with ARIA roles and states
• Add comprehensive accessibility state tracking

The changes improve element detection accuracy by leveraging Chrome's accessibility tree, providing better support for:

• Screen reader compatibility
• ARIA role detection
• Visibility state detection
• Interactive element identification
• Accessibility state tracking

These improvements make Stagehand more reliable for automating accessibility-aware web interactions.

Link to Devin run: https://app.devin.ai/sessions/a35495e6c9ae43f9b145c8b4f4c00275