Fix auto closing of < in markdown code blocks

This reverts commit b811600e.

fixes #41192

This pulls in all the pushed changes after the v3 release and more screen
reader improvements, including:

- Render row debouncer to limit re-rendering of a11y rows
- assertive live region
- Convert \t to nbsp in live region
- Bug fix in parser not exiting to normal parse mode on certain sequences
- Emit selection event on terminal (not SelectionManager)
- Use of resolution event in ScreenDprMonitor

fixes #35032

fixes #41157

- would detect NPE fixed in c4065a8b