Share/synchronize cookie store between widget and quick webengines

Currently cookies are kept separate at runtime. If an application uses widgets from where a cookie is set, and then uses quick based webengine to open the same page again, the set cookie are not visible there. After restart they are visible in both since those cookies are written to disk.

It would be nice if there was some way to share cookie store. Maybe QWebEngineCookieStore could be made a settable property in profile to allow using the same instance across views.