Built-in “Quick Replies” CTA Bar (bottom actions)

[BriceFab]

Many chatbot use-cases need one-tap suggested replies or actions (e.g., “Yes”, “No, thanks”, “Track order”).
Currently developers build this using Composer.topWidget, customMessageBuilder, or slivers, but these are workarounds that lead to inconsistent placement and extra boilerplate.

A built-in CTA bar anchored at the bottom above the composer would:
• Provide a consistent UX for quick replies.
• Simplify state management and theming.
• Avoid repeated custom implementations.

This component could expose a simple list of actions (text or callbacks) and handle layout, keyboard safety, and accessibility out of the box, while remaining optional for those who want full customization.

I've seen this discussion but it's not clear how to deal with #188

Thank you in advance!