refactor(测试跟踪): 缺陷导入对话框样式优化

--bug=1025897 --user=陈建星 【测试跟踪】缺陷管理导入缺陷弹窗样式优化 https://www.tapd.cn/55049933/s/1367932

test-track/frontend/src/business/issue/components/import/IssueImport.vue

@@ -1,5 +1,11 @@
 <template>
-  <el-dialog :visible="visible" v-loading="loading" :title="$t('test_track.issue.import_bugs')" @close="cancel" width="35%">
+  <el-dialog
+    v-loading="loading"
+    width="35%"
+    :visible="visible"
+    :title="$t('test_track.issue.import_bugs')"
+    class="issue-import-dialog"
+    @close="cancel">
     <div>
       <el-row>
         <span style="color: red">*</span> {{ $t('test_track.issue.import_type') }}
@@ -164,4 +170,8 @@ export default {
   font-size: 5px;
   font-weight: 600;
 }
+
+.issue-import-dialog :deep(.el-dialog) {
+  min-width: 500px;
+}
 </style>