feat(infrastructure): Add Limilabs email service and RabbitMQ email queue

- Add LimilabsEmailService for SMTP operations (IEmailService implementation)
- Add RabbitMqEmailQueue for production email queue (RabbitMQ-based)
- Update InMemoryEmailQueue for improved error handling
- Update IEmailQueue interface for RabbitMQ compatibility
- Update DependencyInjection.cs:
  * Switch IEmailService to LimilabsEmailService (Singleton)
  * Switch IEmailQueue to RabbitMqEmailQueue (Singleton)
  * Change IEncryptionService to Singleton (thread-safe)
  * Remove IDmsService registration
- Add required NuGet package references to .csproj

TODO: Add Limilabs.Mail NuGet package (commercial license required)

src/DigitalData.EmailProfiler.Application/Common/Interfaces/IEmailQueue.cs

@@ -10,4 +10,11 @@ public interface IEmailQueue
     Task EnqueueAsync(EmailOutbox email, CancellationToken cancellationToken = default);
     Task<EmailOutbox?> DequeueAsync(CancellationToken cancellationToken = default);
     Task<int> GetQueueDepthAsync(CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Start event-driven consumer that calls callback when message received
+    /// </summary>
+    /// <param name="onMessageReceived">Callback to process received message</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    Task StartConsumerAsync(Func<EmailOutbox, Task> onMessageReceived, CancellationToken cancellationToken = default);
 }