Blurry icons in various Settings dialogs when window scaling set to 2x

Affected are:

• Appearance > Icons: icon previews
• Appearance > Fonts > Sub-pixel order: RGB mode images
• Display > General: information icon in corner of the display image (and probably the star icon for Primary too)
• Display: display images shown in xfce4-display-settings --minimal
• Mouse and Touchpad > Theme: cursor icons and previews

Version: 4.17.0