refactor(quickbi/preview): 修复：quickbi_预览页面四周内边距

src/views/quickbi/preview/index.vue

 <template>
-  <div>
-    <div class="app-container">
-      <div class="container">
-        <iframe :src="iframeURL"
-          frameborder="0"
-          width="100%"
-          height="800px"></iframe>
-      </div>
-    </div>
-  </div>
+  <iframe :src="iframeURL"
+    frameborder="0"
+    width="100%"
+    height="800px"></iframe>
 </template>
 
 <script setup>