fix: visibility of unread notification and underlay in certain scenarios

[isekovanic]

🎯 Goal

This PR should fix 2 things:

• Unreliable visibility of the unread message notification (especially when sending longer messages that would take the last read message out of the viewport)
• Display of the unread message overlay when message sending is delayed (for example, if we send 5-6 consecutive videos which would take time to upload in the offline case)

The general idea is that if the length of the message list changes after the initial time the notification was rendered, we can safely assume that we're present in the channel and do not need to see the notification. Marking a message as unread should still work as intended.

Should also fix this Zendesk ticket.

🛠 Implementation details

🎨 UI Changes

iOS

Before	After

Android

Before	After

🧪 Testing

☑️ Checklist

• I have signed the Stream CLA (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

[Stream-SDK-Bot]

SDK Size

title	develop	branch	diff	status
js_bundle_size	459 KB	459 KB	0 B	🟢

[stream-ci-bot]

🎉 This PR is included in version 7.1.2 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀