**As** an agile user
**I want to** have the existing work package order migrated keeping as much of the order as possible
**so that** I can start working without interruption

**Acceptance criteria**

* The existing `position` column is reused so that the scope of `project_id, sprint_id` is applied to the existing work packages that used to be grouped by `project_id, version_id`


**Technical notes**

* Use the `WorkPackages::RebuildPositionsService` service

* Begin of the insertion~~AddEnd of the insertion Begin of the deletion AddEnd of the deletion a unique contraint Begin of the insertionon~~ `~~project_id, sprint_id~~` This was attempted to be done but drag and drop, creation and update of work packages failed afterwards.End of the insertion Begin of the deletion on `project_id, sprint_id`End of the deletion