[ENH] Expand Person model

[SteveTeece]

Expand the current Person model to include additional fields and multiple addresses. Move age calculations into the person model.

New models:
Person Model

 public partial class Person
    {
        // Private member variables
        private string _fullname;
        
        // Public properties
        public int PersonId { get; private set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string FullName
        {
            get
            {
                _fullname = FirstName + " " + LastName;
                return _fullname;
            }
        }
        public List<Address> Addresses { get; set; }
        public DateTime DateOfBirth { get; set; }
        public string EmailAddress { get; set; }
        public string HomePhone { get; set; }
        public string Mobile { get; set; }
        public byte[] Photo { get; set; }
    }

Address Model:

 public abstract class Address
    {
        /*
         * This class defines an address.  
         * The purpose of this class is to create a custom data type that can be used in other classes
         * where an address is needed.
         * 
         * Create a public property with type Address to use this class.
         */

        // Private member variables

        // Public Properties
        public string UnitNumber { get; set; }
        public string BuildingName { get; set; }
        public string StreetNumber { get; set; }
        public string StreetName { get; set; }
        public string City { get; set; }
        public string State { get; set; }
        public string Postcode { get; set; }
        public string Country { get; set; }
       public AddressType {get; set;}
        public string AddressLine
        {
            get
            {
                return string.Format("{0} {1}, {2}, {3}, {4}, {5}", StreetNumber, StreetName, City, State, Postcode, Country);
            }
        }

    }

Addresstype Enum:

public enum AddressType
 }
       Residential,
       Work,
       Other
}