KFontChooser changes in KF 5.70

[Ahmad Samir]

Hello.

KFontChooser in KF 5.70 will have a new checkbox to toggle showing only monospaced fonts in the font 
family list view (it was inspired by the checkbox in the Konsole font selection dialog).

This clashes with how Konsole is using KFontChooser as Konsole had it's own box that served a 
similar purpose (in reverse), so the font dialog in Konsole will end up having two checkboxes.

I couldn't think of a clean way to handle the issue in Konsole, otherwise I would have created a 
merge request, but I am giving you a heads-up, so that after KF 5.70 is released users wouldn't get 
hit by this issue.

Have a good day.

-- 
Ahmad Samir