[Accessibility] Narration of "suggested actions container empty" is redundant

[compulim]

Screenshots

Version

main

Describe the bug

When using screen reader to navigate around the UIs, the end-user will hear "suggested actions container: empty".

If suggested actions are never used, they will be confused by this UI.

Steps to reproduce

1. Open https://compulim.github.io/webchat-loader
2. Use screen reader navigation to go up (CAPSLOCK + arrows)

Expected behavior

Before the send box, the screen reader will narrate "suggested actions container: empty".

This is redundant. Should consider hide it before first use, or remove the empty if no longer needed.

Additional context

This is related to #2712.

[Bug]