[CLNP-3775] fix: reset new messages on scroll bottom reached (#1138)

Fixes https://sendbird.atlassian.net/browse/SBISSUE-16266

The `newMessages` array was not being reset even after the message list
scroll reached the bottom. This issue was causing the message
notification bar to not disappear properly.
To address the issue, I manually called `resetNewMessages()` under
certain conditions.

Author: AhyoungRyu

src/modules/GroupChannel/components/MessageList/index.tsx

@@ -84,6 +84,7 @@ export const MessageList = (props: GroupChannelMessageListProps) => {
     loadNext,
     loadPrevious,
     setIsScrollBottomReached,
+    resetNewMessages,
   } = useGroupChannelContext();
 
   const store = useSendbirdStateContext();
@@ -167,7 +168,13 @@ export const MessageList = (props: GroupChannelMessageListProps) => {
           scrollDistanceFromBottomRef={scrollDistanceFromBottomRef}
           onLoadNext={loadNext}
           onLoadPrevious={loadPrevious}
-          onScrollPosition={(it) => setIsScrollBottomReached(it === 'bottom')}
+          onScrollPosition={(it) => {
+            const isScrollBottomReached = it === 'bottom';
+            if (newMessages.length > 0 && isScrollBottomReached) {
+              resetNewMessages();
+            }
+            setIsScrollBottomReached(isScrollBottomReached);
+          }}
           messages={messages}
           renderMessage={({ message, index }) => {
             const { chainTop, chainBottom, hasSeparator } = getMessagePartsInfo({