patch 9.2.0346: Wrong cursor position when entering command line window

patch 9.2.0346: Wrong cursor position when entering command line window

Problem:  Wrong cursor position when entering command line window
Solution: Add check_cursor() command to verify the cursor position
          (Hirohito Higashi).

When opening the command-line window with CTRL-F after typing a command
that fills the screen width, the cursor was placed past the end of the
line.  Add check_cursor() after setting State to MODE_NORMAL so the
cursor is adjusted to the last character.

Also fix the cmdwin prefix character (e.g. ':') being drawn on wrapped
continuation rows.  Draw an empty space instead so that the text
alignment is preserved.

closes: #19964

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>