Remove costly calls to the Windows printing framework.
Attempt to bring over a fix for custom page sizes with margins on Mac:

> Respect the custom paper size settings on Mac
>
> When the user added a custom paper size then it would be silently
> ignored when printing on Mac. This now ensures that it is respected when
> appropriate.
> [ChangeLog][Platform Specific Changes][OS X][QtPrintSupport] Respect
> the custom paper size settings when printing.
> Task-number: QTBUG-34700
> Change-Id: I08afe24e0e67a50e9301abf4642c6f65bb0df1fe