chore: ScrollToEventId duration for jump in timeline

lib/pages/chat/chat.dart

@@ -783,7 +783,7 @@ class ChatController extends State<ChatPageWithRoom> {
     inputFocus.requestFocus();
   }
 
-  void scrollToEventId(String eventId) async {
+  void scrollToEventId(String eventId, {Duration? duration}) async {
     var eventIndex = timeline!.events.indexWhere((e) => e.eventId == eventId);
     if (eventIndex == -1) {
       setState(() {
@@ -799,6 +799,7 @@ class ChatController extends State<ChatPageWithRoom> {
     await scrollController.scrollToIndex(
       eventIndex,
       preferPosition: AutoScrollPosition.middle,
+      duration: duration ?? scrollAnimationDuration,
     );
     _updateScrollController();
   }

lib/pages/chat/chat_view.dart

@@ -345,8 +345,10 @@ class ChatView extends StatelessWidget {
                           child: Center(
                             child: FloatingActionButton.extended(
                               icon: const Icon(Icons.arrow_upward_outlined),
-                              onPressed: () => controller
-                                  .scrollToEventId(controller.room.fullyRead),
+                              onPressed: () => controller.scrollToEventId(
+                                controller.room.fullyRead,
+                                duration: Duration.zero,
+                              ),
                               label: Row(
                                 mainAxisSize: MainAxisSize.min,
                                 children: [