Optimize MarkBind for saving as PDF

[damithc]

One area we can focus on optimizing MarkBind is saving as PDF -- as content-intensive pages might be saved as PDF. A specific use case is this textbook.

Steps:

1. Save the abovementioned page as a PDF using the technique given in https://se-education.org/guides/tutorials/savingPdf.html
2. Examine the PDF to locate places where the appearance can be improved
3. Look into ways MarkBind can facilitate those improvements

Some examples:

Unnecessary UI elements:

Wasted space which can be avoided if we support more layout options

Not enough padding:

[EltonGohJH]

I think there are multiple old issues with saving as PDF. I think we can use this issue to collate and investigate all old PDF issues (and close the old one) and make a task list in this issue.

[Tim-Siu]

Unnecessary UI elements are not spotted when printing via Chrome. Not enough padding indeed exists.

Related Printing Issues: #2109 (Can reproduce) #2157 (Cannot reproduce/May have been resolved)