Improve prompt input re-rendering, especially on UNIX systems

This change improves input prompt re-rendering in ConsoleReadLine in a
couple of cases:

1. Where the line wraps.  The new implementation is simpler and handles
   terminal resizing correctly.

2. On UNIX-based systems where escape characters are written for certain
   keypresses like ESC or Backspace.  This change overwrites the
   characters written to the terminal in those cases so that there is no
   extra noise added to the input line.

Author: daviwil