refactor: Entfernte die HandleException Methode aus der CRUDService Klasse und dem Interface

- Die Methode `HandleException` wurde aus der `CRUDService` Klasse entfernt.
- Die Methode wurde ebenfalls aus dem `ICRUDService` Interface entfernt.

DigitalData.Core.Application/CRUDService.cs

@@ -113,15 +113,5 @@ namespace DigitalData.Core.Application
             var entity = await _repository.ReadByIdAsync(id);
             return entity is not null;
         }
-
-        /// <summary>
-        /// Handles exceptions that occur during CRUD operations, providing a structured string.
-        /// </summary>
-        /// <param name="ex">The exception that was caught during CRUD operations.</param>
-        /// <returns>A <see cref="IServiceMessage"/> containing information about the failure, including a user-friendly error message and additional error details.</returns>
-        public virtual string HandleException(Exception ex)
-        {
-            return $"An unexpected error occurred on the server side. Please inform the IT support team.\n{ex.GetType().Name}\n{ex.Message}";
-        }
     }
 }