Better PDF Viewing Performance

[Please describe the Feature Request here]

The PDF view should be more responsive and fast. By that, performance while handling large PDFs should be improved. It should be less jittery when changing the size of the document, text-highlighting should be more precise, and it should minimize flickering when scrolling. On a similar note, resizing should more intuitive and accessible with the mouse/mousepad, rather than just having two fixed resize buttons.

[ Tell us why it is important / how it benefits your workflow here]

This is important because it will facilitate focus. My workflow would be less distracted from the random unexpected flickering. And, reading would simply be so much better since I wouldn’t need to squint while reading, since resizing the document notably causes jittering, among other problems of resizing such as the cumbersome reloading of the PDF.