Draggable: Modified to account resizable handles size in document containment mode, used by ui.dialog. Fixed #9521 ui.Dialog: Resizable dialogs move/resize out of viewport boundary - which results in scrollbar in window

Draggable: Modified to account resizable handles size in document containment mode, used by ui.dialog. Fixed #9521 ui.Dialog: Resizable dialogs move/resize out of viewport boundary - which results in scrollbar in window