학습데이터 다운로드 파일 정보 API 추가

src/main/java/com/kamco/cd/training/model/dto/ModelTrainDetailDto.java

@@ -245,4 +245,13 @@ public class ModelTrainDetailDto {
     private Float iou;
     private Float accuracy;
   }
+
+  @Getter
+  @Setter
+  @NoArgsConstructor
+  @AllArgsConstructor
+  public static class ModelFileInfo {
+    private Boolean fileExistsYn;
+    private String fileName;
+  }
 }