Move of a section must trigger a page refresh in the UE

Moving a section currently brings the order out of sync between backend and UE UI. While it is moved in the backend/document the order is out of sync in UE UI.

To reproduce:
* add a section to a page
* move the new section to the top (or any other place within the page)
* make sure the section is still selected
* add a new block

-> block gets added to the last section