message: core-api: add NotFoundPage to FlatRoutes
diff: * limitations under the License.
  */
  -import { ReactNode, Children, isValidElement, Fragment } from 'react';
  +import React, { ReactNode, Children, isValidElement, Fragment } from 'react';
  import { useRoutes } from 'react-router-dom';
  +import { useApp } from '../app';
  type RouteObject = {
  path: string;
  @@ -71,6 +72,15 @@ type FlatRoutesProps = {
  };
  export const FlatRoutes = (props: FlatRoutesProps): JSX.Element | null => {
  + const app = useApp();
  + const { NotFoundErrorPage } = app.getComponents();
  const routes = createRoutesFromChildren(props.children);
  +
  + // TODO(Rugvip): Possibly add a way to skip this, like a noNotFoundPage prop
  + routes.push({
  + element: <NotFoundErrorPage />,
  + path: '/*',
  + });
  +
  return useRoutes(routes);
  };
  