feat(RAC): Expose useRenderProps hook

[sebald]

Hey, here's a simple addition to the RAC API: by exposing useRenderProps, RAC users can build their own components that integrate more seamlessly with other RAC components.

✅ Pull Request Checklist:

• Included link to corresponding React Spectrum GitHub Issue.
• Added/updated unit tests and storybook for this change (for new code or code which already has tests).
• Filled out test instructions.
• Updated documentation (if it already exists for this component).
• Looked at the Accessibility Practices for this feature - Aria Practices

📝 Test Instructions:

🧢 Your Project: