refactor: 결제 승인일시 예외 메시지 명확화

src/main/java/com/example/sharemind/payApp/application/PayAppServiceImpl.java

@@ -253,7 +253,7 @@ private LocalDateTime parseToLocalDateTime(String dateTimeString) {
 
             return LocalDateTime.parse(formattedString, DateTimeFormatter.ISO_LOCAL_DATE_TIME);
         } catch (DateTimeParseException e) {
-            throw new PayAppException(PayAppErrorCode.DATETIME_PARSE_FAIL);
+            throw new PayAppException(PayAppErrorCode.DATETIME_PARSE_FAIL, dateTimeString);
         }
     }
 }