FGeometrySelectionPreviewis a combinedFGeometrySelectionandFGeometrySelectionEditor. The purpose of this class is to support things like hover-highlighting, where the Selection system needs to be queried but the result is going to be discarded.FGeometrySelectionPreviewcan only be constructed based on a parentFGeometrySelectionEditor, from which it derives it's configuration, which is then how the rest of the system knows what geometry to provide as a preview/etc