[autoform] Avoid two calls to field.process_form for the same field in some cases
when some entity is being created and data include non-inlined relations, the
values for this relation are now stored for later usage, avoiding two calls
to field's process_form method, which may be unexpected for custom fields.
This has been discovered in saem_ref#f5444b1f9770.
Reorganize imports in the test along the way.
Document: cubicweb-doc
Title: CubicWeb Documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/python-cubicweb-documentation/html/index.html
Files: /usr/share/doc/python-cubicweb-documentation/html/*