[A11y] Narrate attachment content inside live region

[compulim]

Version

4.10.1

Describe the bug

Today, for live region, we narrate:

"Bot said, Hi I am Clara! One attachment."

Tomorrow, we want to narrate:

"Bot said, Hi I am Clara! I agree button. I don't agree button."

Also true for card with dropdowns.

Steps to reproduce

1. Go to MockBot
2. Turn on Windows Narrator
3. Type "herocard qna 1"

Expected behavior

The narration should be:

"Bot said, Hi I am Clara! I agree button. I don't agree button."

Additional context

We need to add update a few things

• Update activity middleware to support custom rendering of "live region version" of the activity
  • The middleware must provide a custom render of the "interactive version", which is same as today
  • The middleware is optional to provide a custom render of the "live region version"
• Upgrade all default activity middleware to custom render the live region version, for example
  • Adaptive Cards: retrieve all widgets and custom render it in the live region version
  • Image/animation: instead of saying "one attachment", use the alt text
  • Audio/video: say, "one audio" or "one video"
  • Markdown: say, "rich text"
  • Plain: say, "plain text"
  • File upload/download: say, "file abc.txt of size 12 kB"

[Bug]

[compulim]

Done.