Extend the unit-tests for bindable properties and fix the discovered
binding loop by using {set}ValueBypassingBindings() in the setter of
the duration property.
The code refactoring does not modify the setter logic, because
previously the binding was anyway implicitly removed when calling the
assignment operator. The updated code just does it explicitly.
Task-number: QTBUG-116346
Change-Id: I0f339d182efb60500ee7f12e407f200d739da312
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>
(cherry picked from commit b64e36240b807e6dba783732593036439fec8a62)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
1a779b15b2