Instead of just setting the whole widget as disabled, implement proper
read-only state for these widgets. This fixes an annoying UI issue where
the list / key value widgets can't be scrolled when opening read-only
attribute forms, preventing users from viewing all the entries in
the widget.
The original workaround was only supposed to apply to QList/
QVector of QVariantMaps. By replacing them all in sip we
break mapping of signals defined in c++ which are emitted
by Python code.
Fixes exceptions after running processing algorithms in Qt6
builds.
