UI Automation in Windows Console: add STABILIZE_DELAY and improve "speak typed words" (#9651)
* Add a 30 ms STABILIZE_DELAY to the UIA console (identical to that in legacy consoles).
This helps NVDA process large amounts of text.
* unset _isTyping on interrupt characters, and clear the typed words buffer when enter or tab is pressed.
Note: this will need to be investigated once #8110 is merged.
* Cleanup.
* Add \n