Switching to/from alternate screen doesn't update cursor column
(Based on https://github.com/microsoft/terminal/issues/3545)
printf "\e[9;20H\e[?1049hstart\n"
Expected (xterm): the word "start" printed from row 9, column 20.
Actual: the word "start" printed from row 9, column 1.
The row is preserved as expected. The column is the one that was last used on the alternate screen.
The same happens when switching back from the alt screen, but 1047 has to be used then to spot the behavior, otherwise the cursor position is restored as expected (1049 implicitly doing a DECRC).