Greenfield API: Create User

Slightly big PR because I started refactoring to reduce code duplication between the UI based business logic and the api one.

BTCPayServer.Client/Models/ApplicationUserData.cs

@@ -2,7 +2,41 @@ namespace BTCPayServer.Client.Models
 {
     public class ApplicationUserData
     {
+        /// <summary>
+        /// the id of the user
+        /// </summary>
         public string Id { get; set; }
+        /// <summary>
+        /// the email AND username of the user
+        /// </summary>
         public string Email { get; set; }
+        /// <summary>
+        /// Whether the user has verified their email
+        /// </summary>
+        public bool EmailConfirmed { get; set; }
+        /// <summary>
+        /// whether the user needed to verify their email on account creation
+        /// </summary>
+        public bool RequiresEmailConfirmation { get; set; }
+    }
+
+    public class CreateApplicationUserRequest
+    {
+        /// <summary>
+        /// the email AND username of the new user
+        /// </summary>
+        public string Email { get; set; }
+        /// <summary>
+        /// password of the new user
+        /// </summary>
+        public string Password { get; set; }
+        /// <summary>
+        /// Whether this user is an administrator. If left null and there are no admins in the system, the user will be created as an admin.
+        /// </summary>
+        public bool? IsAdministrator { get; set; }
+        /// <summary>
+        /// If the server requires email confirmation, this allows you to set the account as confirmed from the start
+        /// </summary>
+        public bool? EmailConfirmed { get; set; }
     }
 }