Gets the page ranges a print dialog starts with (PrintPageRange, PDF 1.7), numbered from 1, or null:
implementation dependent.
public IReadOnlyList<PdfPageRange>? PrintPageRange { get; }
ISO 32000-2 §12.2, Table 147: an even number of integers read in pairs, first and last page. A pair that is not two positive integers with first not after last, and an element left over from an odd count, are dropped with a diagnostic.