[FR] Leave tasks unassigned

[m-terlinde]

Is your feature request related to a problem? Please describe. When creating a task, it is often not clear, who in the team will take care of it. Currently, we have to assign the task to someone.

Describe the solution you'd like Set a task to "unassigned"

Describe alternatives you've considered Currently, we evaluated two options:

• Assign the task to the administrator
• Create a user with the name "unassigned" :D

As always, thanks for all your efforts!