Update spacing of configuration widgets
With KF6, KPageView based widgets don't provide their own margins anymore, so we don't need to overwrite the contentMargins of the widget itself.
Also use flat QGroupBox when the groupbox is the only element inside the configuration page to reduce the amount of frames.
Some screenshots:
(Note: I'm not a fan of the x.509 service section being not alligned)
Edited by Carl Schwan