fix(接口测试): 场景执行插件协议请求时，body 访问错误修复

(cherry picked from commit 85f06fb2a5)

frontend/src/views/api-test/scenario/components/step/stepTree.vue

@@ -1257,9 +1257,9 @@
           body: {
             ...request.body,
             jsonBody: {
-              ...request.body.jsonBody,
-              jsonSchema: request.body.jsonBody.jsonSchemaTableData
-                ? parseTableDataToJsonSchema(request.body.jsonBody.jsonSchemaTableData[0])
+              ...request.body?.jsonBody,
+              jsonSchema: request.body?.jsonBody?.jsonSchemaTableData
+                ? parseTableDataToJsonSchema(request.body?.jsonBody?.jsonSchemaTableData?.[0])
                 : undefined,
             },
           },

frontend/src/views/api-test/scenario/components/utils.ts

@@ -137,8 +137,8 @@ export function getStepDetails(steps: ScenarioStepItem[], details: Record<string
         body: {
           ...currentDetail.body,
           jsonBody: {
-            ...currentDetail.body.jsonBody,
-            jsonSchema: currentDetail.body.jsonBody.jsonSchema,
+            ...currentDetail.body?.jsonBody,
+            jsonSchema: currentDetail.body?.jsonBody?.jsonSchema,
             jsonSchemaTableData: [], // 原树形结构存在循环引用，这里要去掉以免 axios 序列化失败
           },
         },