Adding ViewTransitionUtils: not well supported by React (we have too many state updates and async flows to use this).

Note: this worked in the InReferenceToBubble, migrating it from the composer to the last user message.

src/common/util/viewTransitionUtils.ts

@@ -0,0 +1,40 @@
+// import { flushSync } from 'react-dom';
+//
+//
+// // Provide the missing definition for this novel API
+//
+// // Extend the global Document interface
+// declare global {
+//   interface Document {
+//     startViewTransition(updateCallback: UpdateCallback): ViewTransition;
+//   }
+// }
+//
+// type UpdateCallback = () => Promise<any>;
+//
+// interface ViewTransition {
+//   readonly updateCallbackDone: Promise<undefined>;
+//   readonly ready: Promise<undefined>;
+//   readonly finished: Promise<undefined>;
+//
+//   skipTransition(): undefined;
+// }
+//
+//
+// // Perform a view transition, if supported by the browser
+// export async function performViewTransition<T>(callback: () => T) {
+//
+//   // If the browser does not support view transitions, just call the callback
+//   if (!('startViewTransition' in document))
+//     return callback();
+//
+//   // Transition to the new view
+//   const viewTransition = document.startViewTransition(async () => {
+//     if (typeof flushSync !== 'function')
+//       return callback();
+//     return flushSync(() => callback());
+//   });
+//
+//   // Wait for the transition to be ready
+//   // await viewTransition.ready;
+// }