This is an initial implementation that isn't used for any settings yet,
but will be used once `Vec<String>` is implemented.

I also updated the window.with_state api to grant access to a
`Context<S>` app reference instead of just an App.

## Example

<img width="603" height="83" alt="Screenshot 2025-09-09 at 2 15 56 PM"
src="https://github.com/user-attachments/assets/7b3fc350-a157-431f-a4bc-80a1806a3147"
/>


Release Notes:

- N/A