porting from qtwebkit to qtwebengine

[efferre79]

Many distributions are phasing out qtwebkit, look for instance qtwebkit/qtwebkit#1053

What about migrating to qtwebengine? https://doc.qt.io/qt-5/qtwebenginewidgets-qtwebkitportingguide.html

[robert7]

maybe: #197

[prahal]

#236 is a duplicate and has a Draft PR #238
Maybe this one can be closed even if older?