The Navigation Panel order should be used for the PDF Export

Steps to reproduce:

• Create a space with a few children:

  Test Export
  * Alibaba Space
  * Testing TableEdit
  

• Update the title of the pages and see the new order on the navigation

  Test Export
  * 1 - Testing TableEdit
  * 2 - Alibaba Space
  

• Export the

  Test Export

  will all children

Result:

• the PDF export preview displays the order as provided on the Navigation panel
• the export does not follow the order displayed on the Navigation panel -> the TOC keeps the alphabetical order

Expected Result:

• the export follows the order displayed on the Navigation panel