Export separate components of the library

[vbuch]

Feature Request

Feature description

In a library I am working on, I've created a method that needs what is already in PDFObject (preview). It would be really nice if I can reuse that as a dependency instead of copy-pasting it into my code.

The separate components of PDFKit are currently hidden (made private) inside the package and only PDFDocument is exported. Could you consider also exporting other components like PDFObject and PDFAbstractReference?

[blikblum]

This is definitively on the radar since will be required to make encryption support opt-in. But is a breaking change and there are a few changes more urgent