Optimized wiki code (#2566)

* optimized path component

* abstract component

* repair copy bug

* move copy&move&download to list-item

* add modal portal

frontend/src/components/toolbar/dir-operation-toolbar.js

@@ -0,0 +1,19 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+
+const propTypes = {
+
+};
+
+class DirOperationToolbar extends React.Component {
+
+  render() {
+    return (
+      <div></div>
+    );
+  }
+}
+
+DirOperationToolbar.propTypes = propTypes;
+
+export default DirOperationToolbar;