widget: use display monitors configuration
widget: use display monitors configuration

Use display::monitors property to manage display area. Call
update_area_monitor() to update the widget area depending on monitor
configuration

flexVDI/spice-gtk,guodong/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,elmarco/spice-gtk,elmarco/spice-gtk,mathslinux/spice-gtk,SPICE/spice-gtk,SPICE/spice-gtk,fgouget/spice-gtk,guodong/spice-gtk,elmarco/spice-gtk,dezelin/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,fgouget/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,Fantu/spice-gtk,Fantu/spice-gtk,dezelin/spice-gtk,dezelin/spice-gtk,Fantu/spice-gtk,freedesktop-unofficial-mirror/spice__spice-gtk,mathslinux/spice-gtk,SPICE/spice-gtk,fgouget/spice-gtk,guodong/spice-gtk,guodong/spice-gtk,mathslinux/spice-gtk,mathslinux/spice-gtk,SPICE/spice-gtk,flexVDI/spice-gtk,Fantu/spice-gtk,elmarco/spice-gtk,dezelin/spice-gtk