Report terminal window position.
The terminal replies with
xpos is the x position of the terminal window and
ypos is the y position.
cmd = 2 then the position is the position of the inner top-left corner of the window decorations.
🛈 Behaves always as if
cmd = 2.
🛆 Windows with negative coordinates generated output with '-' which creates invalid CSI sequences.
🛆 Windows with negative coordinates generated output with wrapped values (using 16bit)
🛆 Always returns 0, 0 since vte 0.58
🛆 Before 0.58: At least with gnome-terminal as embeder
xpos sometimes wraps around to something close to 65500.(https://gitlab.gnome.org/GNOME/vte/issues/128)