feat: Archive all notifications (#6599)

* feat: Archive all notifications

* use non-modal notification menu

* don't show icons in context menu

app/stores/NotificationsStore.ts

@@ -54,6 +54,20 @@ export default class NotificationsStore extends Store<Notification> {
     });
   };
 
+  /**
+   * Mark all notifications as archived.
+   */
+  @action
+  markAllAsArchived = async () => {
+    await client.post("/notifications.update_all", {
+      archivedAt: new Date().toISOString(),
+    });
+
+    runInAction("NotificationsStore#markAllAsArchived", () => {
+      this.clear();
+    });
+  };
+
   /**
    * Returns the approximate number of unread notifications.
    */