[Development] Adding CPD support to Qt print dialog

[Gaurav Guleria]

Hello all,

I am Gaurav Guleria, a GSoC student, working with Till Kamppeter to add 
and improve Common Print Dialog (CPD) support to existing print dialogs 
like GTK and Qt. More about CPD can be read here: 
https://openprinting.github.io/projects/04-print-dialog/.

I wanted to ask about your opinions on the implementation and the way we 
should proceed with it. I talked with a few people and read this old 
article here: https://wiki.qt.io/Qt-5-QtPrint, which suggests the Qt 
team prefers CPD support as a plugin rather than a direct integration 
into the QPrintDialog.

Just to summarize briefly, implementing CPD support directly in the 
print dialog would mean that the Qt team wouldn't have to worry about 
any future CUPS changes, or any other print backends for that matter, as 
CPD will handle them all instead.

It would be really helpful if you could share your views on this and 
give your suggestions.

Thanks,

Gaurav