Funktion: Hinzufügen von strukturierten Logging-Erweiterungen und Korrektur eines Parameterfehlers

- Hinzufügen der Methoden `LogMessageList` und `LogServiceMessage` für verbessertes Nachrichten-Logging.
- Korrektur der Schreibweise des Parameters `separator`.
- Dokumentation der Methoden für bessere Klarheit.

DigitalData.Core.API/ControllerExtensions.cs

@@ -1,4 +1,5 @@
-using Microsoft.AspNetCore.Mvc;
+using DigitalData.Core.Contracts.Application;
+using Microsoft.AspNetCore.Mvc;
 using System.Text;
 
 namespace DigitalData.Core.API
@@ -44,5 +45,15 @@ namespace DigitalData.Core.API
 
             return controllerBase.StatusCode(500, sb.Length > 0 ? sb.ToString() : null);
         }
+
+        /// <summary>
+        /// Returns an ObjectResult representing an internal server error (status code 500) with optional exception and message details.
+        /// </summary>
+        /// <param name="controllerBase">The ControllerBase instance representing the controller.</param>
+        /// <param name="ex">Optional. The exception that occurred, if any.</param>
+        /// <param name="message">Optional. A custom error message to include in the response.</param>
+        /// /// <param name="messageKey">Optional. A custom error message key to include in the response.</param>
+        /// <returns>An ObjectResult representing an internal server error (status code 500).</returns>
+        public static ObjectResult InnerServiceError(this ControllerBase controllerBase, IServiceMessage? serviceMessage = null) => controllerBase.StatusCode(500, serviceMessage);
     }
 }