feat(notification-outbox): add NotificationOutbox repository

src/ScadaLink.ConfigurationDatabase/ServiceCollectionExtensions.cs

@@ -45,6 +45,7 @@ public static class ServiceCollectionExtensions
         services.AddScoped<ISiteRepository, SiteRepository>();
         services.AddScoped<IExternalSystemRepository, ExternalSystemRepository>();
         services.AddScoped<INotificationRepository, NotificationRepository>();
+        services.AddScoped<INotificationOutboxRepository, NotificationOutboxRepository>();
         services.AddScoped<IInboundApiRepository, InboundApiRepository>();
         services.AddScoped<IAuditService, AuditService>();
         services.AddScoped<IInstanceLocator, InstanceLocator>();