Add pinned message chat event

ts/util/getNotificationDataForMessage.preload.ts

@@ -51,6 +51,7 @@ import {
   isUnsupportedMessage,
   isConversationMerge,
   isMessageRequestResponse,
+  isPinnedMessageNotification,
 } from '../state/selectors/message.preload.js';
 import { getAuthor } from '../messages/sources.preload.js';
 import {
@@ -510,6 +511,10 @@ export function getNotificationDataForMessage(
     };
   }
 
+  if (isPinnedMessageNotification(attributes)) {
+    throw new Error('unimplemented');
+  }
+
   const { poll } = attributes;
   if (poll) {
     return {