Client: Manage QMimeData lifecycle
QMimeData is created by user, it is not taken care of in qtwayland, which will cause memory leak.
It is now handled in qtwayland that when a new QMimeData is set, the previous QMimeData is freed.
Change-Id: Ic502021fe700c7ee10454d94f0d1868901809af7 Reviewed-by: David Edmundson davidedmundson@kde.org Reviewed-by: Qt CI Bot qt_ci_bot@qt-project.org (cherry picked from commit 3af40c6c)