[ENHANCEMENT] Allow copying text from PDFs

[moridius]

Is your feature request related to a problem? Please describe. I use this app for my train tickets. If I want to check in I need my ticket number that is in the PDF. Unfortunately I cannot copy it from there.

Describe the solution you'd like I'd like to be able to copy text from a PDF to Android's clipboard.

Describe alternatives you've considered Currently I open the PDF ticket in a different app for check-in to be able to copy the ticket number.

Additional context I guess this is the right place to mention that this is a fantastic app, with or without that feature. Thank you!