PDF: Table of Contents

[TornaxO7]

Is your feature request related to a problem? Please describe.
I'd like to use rnote to read my lecture-scripts which have about 100 pages+. Xournalpp provides a table-of-contents list which I can click on to get to the given chapter which is pretty neat!

Describe the solution you'd like
Als a little list of the table-of-contents if I import a PDF-File :)

Describe alternatives you've considered
Keep using xournalpp.

Additional context
Here's an image of how xournlpp does it:

[flxzt]

depending to #153, Rnote needs a dedicated PDF annotation mode first before this can be implemented