[Dev Tools] Improve keyboard interactions for menu & overlays (#76754)

This PR implements robust keyboard navigation for the Dev Tools dropdown
menu, and its nested overlays that appear.

Full list of changes:
- Use enum state `open` for making sure only one overlay can be open at
a time
- Implement proper focus trapping through `useFocusTrap` to make sure
focus can never leave the trap
- Fixed bugs related to focusing items in the menu
- Focused index in the menu is retained when closing a nested overlay
- Move all overlay-related logic to `DevToolsInfo`

_Note: We should follow up with an assessment of ARIA attributes on all
these surfaces_


https://github.com/user-attachments/assets/66a36359-1265-40dd-82cc-1032dfdcff28

Closes NDX-927

Author: raunofreiberg