fix(RAC): move native input inside the combobox div

[lixiaoyan]

We have some form binding logic that depends on native form elements being inside the ref element. The current implementation of ComboBox breaks this design. This also makes it more difficult to access the native element for certain reasons (unless we add an extra div wrapper outside). I suggest changing the rendering structure of ComboBox to be consistent with Select, rendering the native form element inside the div instead of as a sibling.

Closes

✅ 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:

[snowystinger]

I'm mostly fine moving it, it doesn't have the same issue as Select #8419 but I like having everything contained within a single root per component when possible.

It hasn't broken any of our tests.

My only hesitations is if anyone else ran into the same issue you did and worked around it by looking at the sibling. Overall though, I think this make more sense.

Going to run chromatic (VRT) on it.
Passed https://www.chromatic.com/build?appId=5f0dd5ad2b5fc10022a2e320&number=1106