Qt: Retranslate GameList header and Filter line

Didn't notice this until I was trying to change the default font
to Comic Sans MS when language is set to English in yuzu.

src/yuzu/game_list.h

@@ -140,6 +140,9 @@ private:
     void AddPermDirPopup(QMenu& context_menu, QModelIndex selected);
     void AddFavoritesPopup(QMenu& context_menu);
 
+    void changeEvent(QEvent*) override;
+    void RetranslateUI();
+
     std::shared_ptr<FileSys::VfsFilesystem> vfs;
     FileSys::ManualContentProvider* provider;
     GameListSearchField* search_field;