Change default issue/task relationship to parent/child from related

Users can create tasks using the issue description by adding a task list and then clicking the "Convert to work item" icon next to the task list item:

The relationship created in this instance is a related relationship, rather than a parent/child relationship. This causes the task to appear in the Linked issues widget.

This should be changed so that no relationship is created by default, but an additional attribute is accepted to optionally set the parent when creating the task. This would cause the task to appear in the Child items widget instead.