Save PDFs in a different resolution than the one used for scanning

[borque]

For good OCR results and a reliable Patch-T recognition a scanning resolution of 300dpi is required.

On the other hand most PDF documents offer a more than sufficient quality for viewing and printing at 150dpi.

In order to reduce the size of the created PDF files without reducing the quality of OCR it might be a good feature to offer settings for two different resolutions, one for scanning, the other for saving.

This was already suggested in 2021 on sourceforge, my apologies for bringing this up again: https://sourceforge.net/p/naps2/discussion/general/thread/70ce8d27d7/

Thanks!