QExplicitSharedDataPointer is meant for value objects, not for shared
objects. Instead switch to using QSharedPointer.

Change-Id: Ib3791bbcfde627a67508f2819e141d8c538a4a50
Reviewed-by: Michael Brüning <michael.bruning@qt.io>
Reviewed-by: Michal Klocek <michal.klocek@theqtcompany.com>