[Prototype] EZP-26309: Prototype the usage of REST Embedding in PlatformUI

[dpobel]

JIRA: https://jira.ez.no/browse/EZP-26309

Description

This is a prototype to use REST Embeddding (implemented in ezsystems/ezpublish-kernel#1741) in PlatformUI. It also requires ezsystems/ez-js-rest-client#79 in the JavaScript REST Client. This is done for 2 parts in PlatformUI:

1. on the "My Drafts" block on the dashboard, this avoids having to load the ContentInfo for each version individually.
2. on the "Version" tab when viewing a Content, this allows to get the Creator of a Version without a new requests.

Outcome

I see 2 issues in the current implementation:

1. it seems like the ContentInfo has been removed from the Location response. This is breaking some parts of PlatformUI.
2. there's a recursion protection which prevents the system from embedding the same object several times. For instance 2 versions can have the same creator (or you can have 2 drafts for the same Content) and this is something very complicated to handle in the PlatformUI.

Other than that, this is working well. The performance improvement on the dashboard block is really interesting and we could so the same in a lots of places! In terms of change, the big thing is in the JavaScript client where we need to change each and every method to accept a new parameter so that we can pass the custom header to request the embedding.

[sunpietro]

Nitpick: response.document.VersionList.VersionItem.forEach() is a better, native way of doing it

[dpobel]

thanks for the nitpicking, but what about the core feature/implementation ? (In case, you missed it, that's only a Prototype)

[sunpietro]

@dpobel I'm going to check it ASAP. Very interesting approach.

[sunpietro]

Nitpick: Object.keys() works natively everywhere