Refactoring

* refactoring
* fixes
* messages
* new interface

SeniorAssistant/Models/Users/Doctor.cs

@@ -7,11 +7,10 @@ namespace SeniorAssistant.Models.Users
         [Column(IsPrimaryKey = true, CanBeNull = false)]
         public string Username { get; set; }
 
-        [Association(ThisKey = "Username", OtherKey = nameof(User.Username), CanBeNull = false)]
-        public User UserData { get; set; }
-
         public string Location { get; set; }
 
         public string Schedule { get; set; }
+
+        public string PhoneNumber { get; set; }
     }
 }