Allow Delegation of Users to Another User [EH-7472]
Allow one user to be delegated to another user, granting the delegated user full view/manage access over the other user's allocated tickets and events.
Introduce a "delegation" relationship between two users in the user list. When User A is delegated to User B, User A gains the ability to view and manage all of User B's tickets and events, as if they were their own.