json-ld: register @vocab on the management api scope

[ndr-brt]

Feature Request

Currently the output json-ld created by the management api lack of the @vocab node.
That's why when we compact the json-ld, every "edc" namespaced property is shown as edc:propertyName and not only propertyName. Not an huge issue, but this could create pitfalls as in #3522 .

Which Areas Would Be Affected?

management api

Why Is the Feature Desired?

api

Solution Proposal

the @vocab should be registered, at least on the management api scope, but it could done also for all the scopes