Add W3ID to the open enumeration /NXobject/identifierNAME@type-attribute

[woutdenolf]

https://manual.nexusformat.org/classes/base_classes/NXobject.html#nxobject-identifiername-type-attribute

[hgoerzig]

Would you add W3ID in general or would you add the PaN part in w3id - so W3ID redirects to https://w3id.org/PaN/... or https://w3id.org/...?
We could also add PaN and say it redirects to https://w3id.org/PaN/...

[woutdenolf]

I propose to add "W3ID" in analogy to "PURL", "URL", "DOI" etc. as an identifier type. So no "PaN".