Improve Diagram Error Handling #221
Description
Prior to bfdd52a, the Dagre.layout method was throwing an unhandled error when States were updated to unidentifiable nodes (id: "").
From the end-user perspective, this would crash the application falling back to Next.js default error handling.
Application error: a client-side exception has occurred (see the browser console for more information).
The Diagram renderer should probably use an <ErrorBoundary> or some other means to more gracefully relay rendering errors.