Fix cooked read reflow under ConPTY

[lhecker]

This delays the CSI J until we know the new origin of the prompt.
That way it's at the right (reflowed) position.

Validation Steps Performed

• conhost
  • Print a ton of text
  • Write a prompt of a hundred chars
  • Resize the window very narrow / wide
  • Works ✅
• Windows Terminal
  • Write a prompt of a hundred chars
  • Resize the window very narrow / wide
  • Works ✅