Make supportInsideInputWidgetEffects control configurable in the widget definition

Since NXS-2168, the control supportInsideInputWidgetEffects is hardcoded and its value is set to true

if (widgetModel instanceof AbstractAggregateWidgetModel) {
                        controlsEl.addElement("control").addAttribute("name",
                                "supportInsideInputWidgetEffects").setText("true");
                    }

But some customers do not want that the results are filtered after each selection in an aggregate widget.
So we need to expose this control in the widget definition alongside the "required" attrbute for instance.