ReportFactory not used any more
With #9511 (closed) the ReportFactory has been removed from the render() method.
This leads to the fact that ReportFactory is obsolete and can be removed from the code.
This also leads to the fact that older reports that still use the 'objects' attribute of the ReportFactory need to be adapted on migration to 5.8. So we should add a note for this in the migration section.