Design non-interrupting alerts

See https://mui.com/material-ui/react-alert/ as an example of this. React Stellar implements [`Alert`](https://nasa-jpl.github.io/react-stellar/?path=/docs/components-alert--docs) which is an interrupting dialog but Stellar in general does not have designs for non-interrupting alerts. Also consider renaming `Alert` to `AlertDialog` to prevent confusion around functionality.