Drop 3.13 incomplete backward compat in edit controller.
It is very old and broken (there is another non-backward-copmpatible
usage of `_cw_entity_fields`), better to remove it instead of fixing.
Closes #3515223.
/*
* cubicweb js mock for unit tests
* This module defines variables and functions used in quite a few places
* in cw js framework that can't be used or guessed without a real CW server
*/
var pageid = 'my-page-id';
function _(message) {
return message;
}