Part of ##40867

Begin of the insertionMotivation:End of the insertion Begin of the deletion Motivation: End of the deletion

* The work package attributes for % Begin of the insertionCompleteEnd of the insertion Begin of the deletion ProgressEnd of the deletion for a work package has two values:
* The value for the the parent work package itself.
* The aggregated value, derived from the work package and its children attributes (before it was children attributes only)
* The derived value computation depends on the work, the status, and the % Begin of the insertionCompleteEnd of the insertion Begin of the deletion progressEnd of the deletion attributes of the work packages Begin of the deletion
* closed status means 100% progressEnd of the deletion
* a work package with work being 0h or unset is excluded from computation

See subtasks below