Tie positions from the shift structure to permissions on the event

[jeriox]

As a planner, I want to delegate certain tasks to a specific person/group of people participating in the event. This could include:

• managing disposition close to the event/on the day
• sending out notifications (e.g. for cancelling the event)
• managing attendance (#1592)
• etc.

Some users already have a position in a predefined unit that logically represents this (e.g. "Wachleiter") and would like for people dispatched for this position to receive an appropriate set of permissions for this event.