dcterms:partOf does not exist

[henrikaskj]

partOf in https://iiif.io/api/presentation/3/context.json does not exist in dcterms, the correct dcterms property would be :isPartOf. @OyvindLGjesdal investigated the issue further and found that there likely was a mixup when "within" was renamed to "partOf". partOf exists in http://www.w3.org/ns/activitystreams.

[azaroth42]

Agreed.

It should be:

https://www.dublincore.org/specifications/dublin-core/dcmi-terms/terms/isPartOf

or

https://www.w3.org/TR/activitystreams-vocabulary/#dfn-partof

But as it's on Canvases and other non-AS-derived classes, propose we should use the correct dcterms predicate.

[azaroth42]

Context is not semantically versioned, we can fix this at any time