Improve accessibility of message list items

[andremion]

🎯 Goal

Improve accessibility of the message list items

🛠 Implementation details

• Merge nodes of message date, unread label, and thread separators
• The onUserAvatarClick parameter in MessagesScreen and MessageContainer is now nullable, as well as the onChannelAvatarClick parameter and its internal MessagesScreenContent composable, allowing to have better semantics if the click is unhandled.
• Add content descriptions for message read status icons and improve the thread footer text handling.
• Add content descriptions for media attachments and message reaction items to enhance accessibility.
• Clear semantics of the other message author to prevent duplication with the avatar semantics.
• Improve content descriptions of the commands button

Out of scope changes

• Fix the order of some assertEquals arguments in UserRobotMessageListAsserts.

🎨 UI Changes

Before	After
Screen_recording_20250829_154007.webm	Screen_recording_20250829_153824.webm

🧪 Testing

Turn Talkback ON in System settings -> Accessibility options

[github-actions]

SDK Size Comparison 📏

SDK	Before	After	Difference	Status
stream-chat-android-client	3.21 MB	3.21 MB	0.00 MB	🟢
stream-chat-android-offline	3.43 MB	3.43 MB	0.00 MB	🟢
stream-chat-android-ui-components	10.51 MB	10.52 MB	0.00 MB	🟢
stream-chat-android-compose	12.69 MB	12.70 MB	0.01 MB	🟢

[VelikovPetar]

Looks pretty good to me!
We should try to follow the approach of defining lambdas as nullable when they are optional(like the changes you did, such as onUserAvatarClick: (() -> Unit)? = null), so that the talkback behaviour is better (for new features)

[sonarqubecloud]

Quality Gate failed

Failed conditions
33.1% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud