[hooks] build EnsureSymmetricRelations{Add,Delete} dynamically
Instead of setting the __select__ attribute at registration time, which
confuses the filterable_selectors cache when running different tests (with
different schemas) in the same process, just make entirely new classes.
Closes #8785708.
.. -*- coding: utf-8 -*-
Server Architecture
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.. image:: images/server-class-diagram.png
`Diagramme ArgoUML`_
[FIXME]
Make a downloadable source of zargo file.
.. _`Diagramme ArgoUML`: cubicweb.zargo