perf(src/packages): 优化3D模型列表，无数据无暂无数据内容

@@ -54,7 +54,14 @@
           </n-dropdown>
         </n-space>
       </div>
-      <n-grid style="margin-top: 16px" :x-gap="20" :y-gap="20" cols="2 s:2 m:3 l:4 xl:4 xxl:4" responsive="screen">
+      <n-grid
+        v-if="list && list.length"
+        style="margin-top: 16px"
+        :x-gap="20"
+        :y-gap="20"
+        cols="2 s:2 m:3 l:4 xl:4 xxl:4"
+        responsive="screen"
+      >
         <n-grid-item v-for="(item, index) in list" :key="item.id">
           <div style="display: none">{{ index }}</div>
           <project-items-card
@@ -68,6 +75,11 @@
           ></project-items-card>
         </n-grid-item>
       </n-grid>
+      <div  v-else style="height: calc(100vh - 40vh);display: flex;align-items: center;justify-content: center">
+        <n-empty description="暂无数据">
+          <template #extra> </template>
+        </n-empty>
+      </div>
     </div>
     <div class="list-pagination">
       <n-pagination