[ML 0.1/UI.04.7] - Fix Compose message list UI and layout issues

[rafaeltonholo]

Blocked by

• [ML 0.1/UI.04.2] - Implement legacy message list loading bridge #10775

Description

Collection of UI and layout fixes for the Compose message list discovered during integration: bottom padding, ComposeView height, swipe thresholds for different screen sizes, scroll behaviour, and dead code removal.

Acceptance Criteria

• Message list LazyColumn has proper bottom padding.
• ComposeView height set to match_parent in fragment layout.
• Swipe thresholds are adjusted based on window size class.
• BannerInlineListScrollBehaviour height check and onPostFling logic refined.
• Dead code removed from MessageListFragment.