[Win32] Only scale menu item images on monitor-specific scaling #2537

The current mechanism to adapt the size of menu item images based on
Windows system metrics, primary monitor zoom at startup and the current
monitor zoom ensures that menu item images always fit to the required
size for that menu. Since menus and their sizes are managed by the OS,
adapting the image size as currently implemented leads to the best
fitting image sizes.
However, this behavior is incompatible with the assumptions one could
previously make on the sizes of those images. In particular, depending
on the used auto-scale mode different kinds of scaling for those images
were in place.

To achieve the best solution for all cases, this change results in the
following:
- When monitor-specific scaling is enabled, menu item images are
properly scaled as required for the menu. This is independent of whether
any other additional legacy settings regarding auto-scaling is made,
which will be overwritten by this.
- When monitor-specific scaling is disabled, the previous behavior is
restored such that images are just scaled depending on the auto-scale
mode but do not take into account which size is actually needed for that
menu.

Fixes #2537

Author: HeikoKlare

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/MenuItem.java

@@ -907,6 +907,9 @@ private long getMenuItemIconSelectedBitmapHandle() {
 }
 
 private int adaptZoomForMenuItem(int currentZoom, Image image) {
+	if (!display.isRescalingAtRuntime()) {
+		return DPIUtil.getZoomForAutoscaleProperty(currentZoom);
+	}
 	int primaryMonitorZoomAtAppStartUp = Win32DPIUtils.getPrimaryMonitorZoomAtStartup();
 	/*
 	 * Windows has inconsistent behavior when setting the size of MenuItem image and