Falken.Echelon.Data.Entities.Camps.CampRegistration
One athlete's seat in a camp. Belongs to a Falken.Echelon.Data.Entities.Camps.CampRegistration.CampRegistrationGroup.
Stores snapshot fields (name, DOB, gender, CMP, class, years) so the registration
is self-contained even when the Athlete match is still pending review.