[rtags] Allow to 'derive' rtags Since some releases, rtags (structure underlying uicfg) have selector and may be copied using something like: new_rtags = deepcopy(original_rtags) new_rtags.__module__ = __name__ new_rtags.__select__ = custom_selector The problem is that starting from that, both rtags wil diverge and changes in original_rtags won't be considered, while we usually want to set a few specific rules only in new_rtags. To fix this problem, this cset introduces the notion of "derivated/parent" rtag, eg: new_rtags = original_rtags.derive(__name__, custom_selector) Beside easier copying, when using the above method changes in original_rtags which are not overriden by new_rtags will be considered since it only hold its specific rules but look among its parent chain for non-found keys. Along the way, flake8 unittest_rtags. Closes #16164880

Ajouter des entités
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Pour un administrateur, la création des objets est toujours possible directement dans la `page de gestion de site`_.

.. _`page de gestion de site`: ../manage

Pour les utilisateurs, la page principale ou la boîte d'action des entités vous permettra la création de nouveaux contenus.
L'intérêt de la dernière méthode est de faciliter l'édition de la relation entre les objets.