Managers can handover the space

[exalate-issue-sync]

Story

As an organization we need an easy way to "hand over" project or team data when responsibilities change.

AC

• Managers can promote other members of a space to managers
• Managers can remove themself from the Space
• Managers can downgrade their Role
• If there's only one Manager left, that Manager can't change their role or remove themself

[exalate-issue-sync]

Michael Barz commented: Assigned to [~jfd] because he is the buddy for André Duffek