Change: Hide bevel for resizeable sparse layout windows. (#11572)

When clicked, the button is still highlighted to show that it is active.

The bevel is controlled with widget_data by RWV_SHOW_BEVEL or RWV_HIDE_BEVEL values.

src/newgrf_gui.cpp

@@ -1963,7 +1963,7 @@ static const NWidgetPart _nested_newgrf_widgets[] = {
 		/* Resize button. */
 		NWidget(NWID_HORIZONTAL),
 			NWidget(NWID_SPACER), SetFill(1, 0), SetResize(1, 0),
-			NWidget(WWT_RESIZEBOX, COLOUR_MAUVE),
+			NWidget(WWT_RESIZEBOX, COLOUR_MAUVE), SetDataTip(RWV_HIDE_BEVEL, STR_TOOLTIP_RESIZE),
 		EndContainer(),
 	EndContainer(),
 };