[ChangeLog][QtCore][QByteArray] Remove method overloads taking
QString as argument, all of which were equivalent to passing the
toUtf8() of the string instead.
Change-Id: I9251733a9b3711153b2faddbbc907672a7cba190
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>