[fix] Versioned Resources API

[subiabre]

We were lacking a descriptive way to shape polymorphic relationships in the API.

Main offender was in the Version API resource, which used to embed the full data of any versioned resource in a version resource without context of what the embed object was and what to expect for it. This PRs adds a middle EmbeddedResource object that includes the ID of the object, the IRI to it (which includes the name for the object collection and hence a way to tell what is the object) and the reconstructed object itself data for that version.

It also aims to fix other important issues with Version resources:

• No way to tell what the embedded object in a Version resource output is.
• Not serving the full object data as it was at that point in the version resource.
• No clear spec for how to work with Version resources and X versioned resource versions. Relevant literature: AWS S3 ListObjectVersions API Reference, AWS S3 GetObject API Reference, RESTful URLs for distinct versions of a resource, Accessing versions/revisions of an object in a RESTful API