feat/seasearch: add wiki search api (#6606)

* feat/seasearch: add wiki search api

* optimize variable name

* feat(wikisearch): add simple ui for wiki search

* chore: delete redundant code

frontend/src/pages/wiki2/side-panel.js

@@ -14,6 +14,7 @@ import { Utils } from '../../utils/utils';
 import WikiExternalOperations from './wiki-external-operations';
 import WikiTrashDialog from './wiki-trash-dialog';
 import { DEFAULT_PAGE_NAME } from './constant';
+import Search from '../../components/search/search';
 
 import './side-panel.css';
 
@@ -176,6 +177,12 @@ class SidePanel extends Component {
             </div>
           }
         </div>
+        <Search
+          repoID={wikiId}
+          onSearchedClick={this.onSearchedClick}
+          placeholder={gettext('Search')}
+          isWiki2={true}
+        />
         <div className="wiki2-side-nav">
           {isLoading ? <Loading/> : this.renderWikiNav()}
         </div>