Change Assigned To in Task board

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As a team member I want an easy way to change Assigned To on an already started (In Progress) Task so that our team can work as agile as intended.

Suggestion: When starting to drag the Task not only a "Cancel Transition" drop area should be visible, also an "Assign" drop area should be visible like following:
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| Assign | Cancel Transition |
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Dropping to Assign should reassign the task (to the selected user in the "Assign tasks to"-list).