Add the option to customize the order of field types in field type groups

And forgot to postpone the issue on 📌 [PP1] Refine field descriptions Active

Following up on a suggestion to do user testing on this. To design a test I would need to know:
• Type of Drupal user likely to use this functionality (and therefore impacted by a change to the interface)
• Typical scenario in which the user would encounter this interface (e.g. when would they need/want to change the order of fields types in field type groups?)
• Desirable outcome from the scenario and problem the change in interface has addressed (e.g. we want to ensure the Drupal user can distinguish between the field types and field groups because not being able to do so would result in [what are the tangible negative consequences of the problem not being addressed])
Reviewing the comments above it seems @rkoller has gained input on target Drupal users the changes would impact so I am not sure if further testing is still required? and if so which unresolved questions this would seek to address?