Allow custom menu class to be passed in to OO.ui.ButtonMenuSelectWidget
Allow custom menu class to be passed in to OO.ui.ButtonMenuSelectWidget

This allows greater flexibility in custominzing the menu. Since the
menu widget is configured with a reference to the ButtonMenuSelectWidget
itself, pass the class name rather than an already-constructed menu.

Bug: T315240
Change-Id: Ia62e7df453744a856d2525d1db09be900dd19b53

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui