Support container updates

First off: this issue is different than creating LDPC on route to creating an LDP-RS as a member of an LDPC that doesn't exist yet. That particular case was covered in https://github.com/solid/node-solid-server/pull/513.

This issue is about creating or updating an LDPC (ie an LDP-BC, at the time of this writing). It will conform to LDP provided that the information in the update payload doesn't get in the way of changing the containment triples ( https://www.w3.org/TR/ldp/#h-ldpc-put-mbrprops ). So, for example, adding a label to a container (<> rdfs:label "Foo") would be fine, but PUT/PATCH that inserts or deletes ldp:contains relations should not succeed.

The use cases are generally about including additional "metadata" as part of the container description. It is partly discussed in https://github.com/solid/node-solid-server/issues/547 .

If this feature is implemented, https://github.com/solid/node-solid-server/issues/547 can be revisited, and as far as I can tell, the feature where updating a container's description through /.meta can be removed altogether (as interacting directly with the URI in question would be generally preferable.)

Edit: rel="describedBy" .meta in HTTP header can also be dropped as the interaction will only go through container URI, and that .meta will only be internal to the server.

Commencez par examiner les exigences de mise à jour des conteneurs LDP et la discussion associée dans l’issue #547, puis localisez le point d’entrée du serveur qui gère les mises à jour d’une URI LDPC. Déterminez comment les payloads PUT et PATCH traitent les triplets ldp:contains par rapport aux autres métadonnées. Le travail est considéré comme terminé lorsque les métadonnées du conteneur peuvent être mises à jour via l’URI du conteneur sans autoriser les modifications du containment, et que le comportement .meta décrit n’est plus nécessaire.