The `--input-page-ranges` option needs to be ported to current, PDFio-based libcupsfilters

@uddhavphatak on your replacement of QPDF use to PDFio use in libcupsfilters (https://github.com/OpenPrinting/libcupsfilters/pull/71) you have dropped the new --input-page-ranges option which got added by OpenPrinting/cups-filters#444 to fix OpenPrinting/cups-filters#365. Could you re-introduce it?

@ValdikSS wrote in OpenPrinting/cups-filters#690:

I just accidentally discovered input-page-ranges option which does exactly what the user expects with number-up, and has been contributed in https://github.com/OpenPrinting/cups-filters/pull/444 as a way to fix https://github.com/OpenPrinting/cups-filters/issues/365 (which is the same bug report as this one).

-o number-up=2 \
-o input-page-ranges=3-4 \

to print pages 3 and 4 in a single page.

It is supported only in cups-filters/libcupsfilters 2.0.x and 2.1.x (QPDF-based).

It haven't been backported to 1.x, and also not supported with the fresh PDFio-based pdftopdf (yet, as of libcupsfilters 2.2.1 release).
I've mentioned it in https://github.com/OpenPrinting/libcupsfilters/issues/239#issuecomment-5583891443, ideally it should be ported to PDFio pdftopdf as well.

Start by comparing the PDFio-based pdftopdf implementation in libcupsfilters with the earlier QPDF-based behavior from OpenPrinting/cups-filters#444 and the replacement described in pull request #71. Reintroduce the input-page-ranges behavior so the documented number-up example selects pages 3 and 4, then verify that this works in the current PDFio-based filter.