重构；DynamicLayout组件重写，移除blog.config.js中的MAPPING配置

lib/utils/index.js

@@ -204,6 +204,9 @@ export function getQueryVariable(key) {
  * @returns {string|null}
  */
 export function getQueryParam(url, param) {
+  if (!url) {
+    return ''
+  }
   // 移除哈希部分
   const urlWithoutHash = url.split('#')[0]
   const searchParams = new URLSearchParams(urlWithoutHash.split('?')[1])