Konnect entities: implement konnectID control plane ref

[pmalek]

Problem statement

Konnect entities (implemented in #370) provided support for referencing Konnect ControlPlanes via konnectNamespacedRef.

A separate type of reference - konnectID - has also been prepared but not implemented yet.

This issue tracks the effort of implementing that so that users can reference Konnect CPs by ID:

kind: KongService
apiVersion: configuration.konghq.com/v1alpha1
metadata:
  name: service-2
  namespace: default
spec:
  name: service-3
  host: example.com
  controlPlaneRef:
    type: konnectID
    konnectID: 2b08d44d-d0f9-4cfc-b1d8-111111111

Acceptance criteria

• As a user I can use konnectID control plane reference for binding my entities to Konnect CPs by ID.