don't override req.form['vid'] in the publisher's error_handler closes #5359234

when some inlined relation is set using cw_edited, its security shouldn't be checked. It's currently checked anyway because upon modification of `cw_edited`, `entity.skip_security` is updated to avoid security checking, but this is only considered for attributes, not relations. Closes #5477315

[test] stop depending on the email cube for hooks test Backport necessary part of its schema.