fix(接口测试): 场景导入提示问题

--bug=1009572 --user=lyh
【接口测试】场景导入没反应
https://www.tapd.cn/55049933/s/1092947

backend/src/main/java/io/metersphere/api/service/ApiAutomationService.java

@@ -1170,7 +1170,7 @@ public class ApiAutomationService {
 
         if (CollectionUtils.isNotEmpty(list)) {
             LogUtil.error("import scenario fail, custom num is exist: " + scenarioWithBLOBs.getCustomNum());
-            return scenarioWithBLOBs;
+            MSException.throwException(Translator.get("import_fail_custom_num_exists") + ": " + scenarioWithBLOBs.getCustomNum());
         }
 
         if (StringUtils.equals("fullCoverage", apiTestImportRequest.getModeId())) {

backend/src/main/resources/i18n/messages_en_US.properties

@@ -223,6 +223,7 @@ delete_check_reference_by=be referenced by Scenario
 not_execute=Not execute
 execute_not_pass=Not pass
 execute_pass=Pass
+import_fail_custom_num_exists=import fail, custom num is exists
 #authsource
 authsource_name_already_exists=Authentication source name already exists
 authsource_name_is_null=Authentication source name cannot be empty

backend/src/main/resources/i18n/messages_zh_CN.properties

@@ -223,6 +223,7 @@ delete_check_reference_by=被场景引用
 not_execute=未执行
 execute_not_pass=未通过
 execute_pass=通过
+import_fail_custom_num_exists=导入失败，自定义ID已存在
 #authsource
 authsource_name_already_exists=认证源名称已经存在
 authsource_name_is_null=认证源名称不能为空

backend/src/main/resources/i18n/messages_zh_TW.properties

@@ -223,6 +223,7 @@ delete_check_reference_by=被場景引用
 not_execute=未執行
 execute_not_pass=未通過
 execute_pass=通過
+import_fail_custom_num_exists=導入失敗，自定義ID已存在
 #authsource
 authsource_name_already_exists=認證源名稱已經存在
 authsource_name_is_null=認證源名稱不能為空