GC Data image scaling Bugfix

This commit fixes the image scaling bug in GC data. The image was scaled
with the native zoom of the GC Data instead of the zoom. This leads to
the the problem of no image drawn but just a white background. The image
is only visible when the zoom and nativeZoom are the same. This behavior
can be seen if the IDE is started at i.e. 125% zoom level on the default
monitor. Hence, in this case the zoom is set to 100 and nativeZoom is
125. And due to wrong scaling, the lineNumberRulerColumn and minimize
and maximize button images are not visible but rather just a white
background is visible. This fix provides the right scaling to the
image in the GC Data using the zoom but not the nativeZoom level
as per the standard.

Contributes to #62 and #127

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/GC.java

@@ -3932,7 +3932,7 @@ void init(Drawable drawable, GCData data, long hDC) {
 	}
 	Image image = data.image;
 	if (image != null) {
-		data.hNullBitmap = OS.SelectObject(hDC, Image.win32_getHandle(image, data.nativeZoom));
+		data.hNullBitmap = OS.SelectObject(hDC, Image.win32_getHandle(image, DPIUtil.getZoomForAutoscaleProperty(data.nativeZoom)));
 		image.memGC = this;
 	}
 	int layout = data.layout;