More information about monitor in xrandr 1.5, see
https://keithp.com/blogs/MST-monitors/
Since this change, screen is logical instead of physical.
If xrandr 1.5 and later is installed, Qt screen info will get
from xrandr monitor object instead of xrandr output if only have
1.2 to 1.4.
Users can manipulate monitor as they want, for example, a
combination for two physical screens, half of one screen and etc.
Didn't have chance to access MST monitors, but it should work
if xrandr monitor object was created automatically.
[ChangeLog][xcb] Qt screen info will get from xrandr monitor
object if 1.5 is installed.
Fixes: QTBUG-65457
Change-Id: Iad339cc0d4293b2403b4ef6bf6eb770feb3e685f
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>
