fix: channel list stale last message (#3534)

## 🎯 Goal

This PR fixes an issue where regaining connection (or just loading the
app with offline mode enabled) would not properly update the last
message for any channels that've changed in the interim.

The reason for this was a very old (seemingly) problem with how
`channel.lastMessage()` is calculated, completely bypassing the actual
last message and not reloading the state at all (even though the
channels would actually swap places as they should and their internal
state would be correct).

This will be ported to V9 as well soon after.

## 🛠 Implementation details

<!-- Provide a description of the implementation -->

## 🎨 UI Changes

<!-- Add relevant screenshots -->

<details>
<summary>iOS</summary>


<table>
    <thead>
        <tr>
            <td>Before</td>
            <td>After</td>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>
                <!--<img src="" /> -->
            </td>
            <td>
                <!--<img src="" /> -->
            </td>
        </tr>
    </tbody>
</table>
</details>


<details>
<summary>Android</summary>

<table>
    <thead>
        <tr>
            <td>Before</td>
            <td>After</td>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>
                <!--<img src="" /> -->
            </td>
            <td>
                <!--<img src="" /> -->
            </td>
        </tr>
    </tbody>
</table>
</details>

## 🧪 Testing

<!-- Explain how this change can be tested (or why it can't be tested)
-->

## ☑️ Checklist

- [ ] I have signed the [Stream
CLA](https://docs.google.com/forms/d/e/1FAIpQLScFKsKkAJI7mhCr7K9rEIOpqIDThrWxuvxnwUq2XkHyG154vQ/viewform)
(required)
- [ ] PR targets the `develop` branch
- [ ] Documentation is updated
- [ ] New code is tested in main example apps, including all possible
scenarios
  - [ ] SampleApp iOS and Android
  - [ ] Expo iOS and Android

Author: isekovanic

package/src/components/ChannelPreview/hooks/useChannelPreviewData.ts

@@ -25,7 +25,7 @@ export const useChannelPreviewData = (
 ) => {
   const [forceUpdate, setForceUpdate] = useState(0);
   const [lastMessage, setLastMessageInner] = useState<LastMessageType>(
-    () => channel.state.messages[channel.state.messages.length - 1],
+    () => channel.state.latestMessages[channel.state.latestMessages.length - 1],
   );
   const throttledSetLastMessage = useMemo(
     () =>
@@ -44,7 +44,7 @@ export const useChannelPreviewData = (
   const { forceUpdate: contextForceUpdate } = useChannelsContext();
   const channelListForceUpdate = forceUpdateOverride ?? contextForceUpdate;
 
-  const channelLastMessage = channel.lastMessage();
+  const channelLastMessage = channel.state.latestMessages[channel.state.latestMessages.length - 1];
   const channelLastMessageString = `${channelLastMessage?.id}${channelLastMessage?.updated_at}`;
 
   const refreshUnreadCount = useMemo(