Fix adding user properties to UserInfo context (#243)

* Fix updating the user preferences

* Fix adding user properties to UserInfo context

* Fix adding user properties to UserInfo context

* Make the dictionaries merge code more imperative

backend/src/Notifo.Domain/Integrations/IntegrationExtensions.cs

@@ -6,13 +6,31 @@
 // ==========================================================================
 
 using Notifo.Domain.Users;
+using Notifo.Infrastructure.Collections;
+using System.Collections.Generic;
 
 namespace Notifo.Domain.Integrations;
 
 public static class IntegrationExtensions
 {
     public static UserInfo ToContext(this User user)
     {
-        return new UserInfo { Id = user.Id, EmailAddress = user.EmailAddress, PhoneNumber = user.PhoneNumber, Properties = user.SystemProperties };
+        var properties = new Dictionary<string, string>(user.Properties);
+
+        if (user.SystemProperties != null)
+        {
+            foreach (var (key, value) in user.SystemProperties)
+            {
+                properties[key] = value;
+            }
+        }
+
+        return new UserInfo
+        {
+            Id = user.Id,
+            EmailAddress = user.EmailAddress,
+            PhoneNumber = user.PhoneNumber,
+            Properties = properties.ToReadonlyDictionary()
+        };
     }
 }