List of approvers are not kept in splitted CR

Reproduction steps:

• Create page A with approvers Foo and Bar
• Create page B with approvers Buz and Baz
• Create a CR including changes from both A and B
• Update rights of A and B so that they are incompatible

Expected results:

• a CR is created for A and contains approvers Foo and Bar
• a CR is created for B and contains approvers Buz and Baz

Obtained results:

• two CRs are created containing changes for A and B but list of approvers are empty

Note that if the list of approvers has been manually edited in the CR, we should copy the entire list of approvers instead of reacreating it from the pages.