[AND-296] Expose scrollToFirstUnreadMessage on MessageListViewModel.

[VelikovPetar]

🎯 Goal

Exposes the scrollToFirstUnreadMessage method from the MessageListController on the MessageListViewModels.

Additionally, fixes a bug where the chatClient.loadMessagesAroundId wasn't called, when calling scrollToFirstUnreadMessage when the message wasn't already loaded.

🛠 Implementation details

• Expose scrollToFirstUnreadMessage on MessageListViewModel(compose)
• Expose scrollToFirstUnreadMessage on MessageListViewModel(xml)
• Fix chatClient.loadMessagesAroundId not called:

messages.firstOrNull { it.id == unreadLabel.lastReadMessageId }
                ?.let { messages.focusUnreadMessage(it.id) }
                ?: {  // <- This was never called as it is lambda that wasn't invoked
                    scope.launch {
                        chatClient.loadMessagesAroundId(cid, unreadLabel.lastReadMessageId)
                            .await()
                            .onSuccess { channel -> channel.messages.focusUnreadMessage(unreadLabel.lastReadMessageId) }
                    }
                }

🎨 UI Changes

Demo for bugfix:

Before	After
before.mp4	after.mp4

🧪 Testing

1. Open XML sample app
2. Ensure there is a conversation with an unread message which is not yet loaded (older than the 30th message)
3. Tap on the "Unread messages" floating badge
4. You should now be scrolled to the first unread message (after a brief delay while the messages are loaded)

[github-actions]

SDK Size Comparison 📏

SDK	Before	After	Difference	Status
stream-chat-android-client	3.17 MB	3.17 MB	0.00 MB	🟢
stream-chat-android-offline	3.38 MB	3.38 MB	0.00 MB	🟢
stream-chat-android-ui-components	7.87 MB	7.87 MB	0.00 MB	🟢
stream-chat-android-compose	8.75 MB	8.75 MB	0.00 MB	🟢

[sonarqubecloud]

Quality Gate failed

Failed conditions
0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud