Add "Member name is required" to ALL lesson bookings under Instructor settings

The ability to add a "Member name is required" to ALL lesson bookings under Instructor settings. Right now, it shows a minimum of 2 names needed, however for private lessons this number should be 1. 

The reason for this is because we want to avoid a pro booking a court in the future, just to have the court, and then worrying about who they are going to coach later. Essentially, we are trying to find a way that all lesson books are made with the intent that "member x" asked for a lesson at this time.