Allow cross namespaced Konnect Control Plane references

[pmalek]

Problem Statement

ControlPlaneRef allows setting the referenced ControlPlane.

One of the types of this reference is KonnectNamespacedRef.

This task tracks the implementation of cross namespace references between entities and Konnect ControlPlanes.

Proposed Solution

Additional Information

Related #9

Acceptance Criteria

• As a user, I can reference a KonnectControlPlane in a different Namespace.