Break preview lines on IND to support chafa in preview window on tmux

chafa ends each row of a Kitty Unicode placeholder image with CUB + IND
instead of a newline, so that an image drawn at a column offset survives
ONLCR, which would rewrite the newline as CR NL and pull the cursor back
to column 0. Both sequences were dropped, so the image arrived as a single
line and was re-wrapped, shifting every row after the first by the width
of the wrap sign. Without wrapping it was truncated to its first row.

The column is tracked across the breaks and restored with padding, so an
image indented by the preview command keeps its indent.

Fix #4885

CHANGELOG.md

@@ -1,6 +1,10 @@
 CHANGELOG
 =========
 
+0.74.3
+------
+- Fixed an image from a preview command being torn apart when its rows are separated by IND instead of newlines, as `chafa` does under tmux (#4885)
+
 0.74.2
 ------
 - Performance optimizations for short queries