Make `ApplicationDescription` ID a top-level attribute

[Silvanoc]

Description

Currently the ID of an ApplicationDescription is "hidden" as the attribute id of the 2nd-level object Metadata.

Motivation

An object identifier should have visibility at the highest object level.

Proposed Solution (optional)

Promote the Metadata attribute id to become the ApplicationDescription attribute id.

[Silvanoc]

@arne-broering any opinion on this?

[arne-broering]

@arne-broering any opinion on this?

Yes I agree with you, it makes sense to move the ID up to the top-level attributes.

[Silvanoc]

@arne-broering please follow discussion in #163. Apparently that structure comes from an initial approach to make those resources K8s CRD-conform. So the decision is rather is we want to be CRD-conform (then the ids remain where they are) or not (in which case they can become top-level attributes).