[uicfg] give a set_fields_order method to the primary view display control
Hence it is nicely symmetrical with the fields kwargs.
Closes #2741963.
#! /bin/sh -e#if [ "$1" = configure ]; then if which install-docs >/dev/null 2>&1; then install-docs -i /usr/share/doc-base/cubicweb-doc fifi#DEBHELPER#exit 0