Introduce KAdjustingScrollArea
A ScrollArea ideal for vertical scrollable widgets and dialogs.
This is upstreaming from a scrollbar copied in many places: https://invent.kde.org/pim/kleopatra/-/blob/master/src/utils/scrollarea.h?ref_type=heads https://invent.kde.org/pim/libkleo/-/blob/master/src/ui/adjustingscrollarea.h https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gpgpass.git;a=blob;f=src/widgets/adjustingscrollarea.h;h=2b048cf4de3a666e711f81a68cbdcaab2c18a642;hb=HEAD
I got the authorization from Till (KDAB) for the relicing from gpl to lgpl.
Edited by Carl Schwan