feat: pdf 预览组件中图片采用缓存组件代替

src/pages/common/viewer/pdf.vue

@@ -38,7 +38,7 @@
 <template>
     <view class="wrap">
         <template v-if="images.length > 0">
-            <fui-lazyload
+            <CacheImage
                 class="image"
                 v-for="(item, index) in images"
                 :key="item.src"