Adding SzGui project

SzCore/SzDataHandler.cs

@@ -22,6 +22,8 @@ public class SzDataHandler
         try
         {
             var json = SZ.Parser.SerializeDatasetToJson(dataset);
+            var evalResult = await SZ.Evaluator.EvaluateDatasetAsync(dataset);
+            if (!evalResult.IsSuccess) return SzResult<bool>.Failure($"Could not save dataset, evaluation failed: {evalResult.Error!}");
             var success = await SZ.LocalFileManager.SaveFileAsync(datasetPath, json, ct);
             return success ? SzResult<bool>.Success(true) : SzResult<bool>.Failure("Failed to write dataset file.");
         }
@@ -246,4 +248,4 @@ public class SzDataHandler
         }
     }
     #endregion
-}
+}

SzCore/SzEvaluator.cs

@@ -109,4 +109,4 @@ public class SzEvaluator
         var errString = errors.ToString().Trim();
         return string.IsNullOrEmpty(errString) ? SzResult<bool>.Success(true) : SzResult<bool>.Failure(errString);
     }
-}
+}