Allow CR author to refactor reference of pages in case of move/rename

In case of a rename or a move of a published page which have opened CR, right now the CR will consider that the page with changes does not exist.
We should probably not refactor automatically all the CR with changes in case of move/rename since the author might want to keep the changes for the previous location.
However we should have a mechanism to prevent the author that the page moved and to allow them to refactor the reference in the CR to point to the new location.