Show error message when canvas to export is too big (#1256) (#2210)

Co-authored-by: dwelle <luzar.david@gmail.com>

src/components/TopErrorBoundary.tsx

@@ -73,7 +73,7 @@ export class TopErrorBoundary extends React.Component<
 
   private errorSplash() {
     return (
-      <div className="ErrorSplash">
+      <div className="ErrorSplash excalidraw">
         <div className="ErrorSplash-messageContainer">
           <div className="ErrorSplash-paragraph bigger align-center">
             {t("errorSplash.headingMain_pre")}