Binding CR should not have a ControllerReference

[pdettori]

Motivation:
I have a higher level Custom Resource that composes and instantiate the Service and Binding CR. The higher level CR sets
the ControllerReference in the binding CR because it is managing its lifecycle, but this causes the Binding controller to fail
because a CR cannot have two owner references:

2020-09-24T10:06:36.029-0400    ERROR   controller-runtime.controller   Reconciler error        {"controller": "binding", "request": "default/my-translator-bbjb4-kttvx", "error": "Object default/my-translator-bbjb4-kttvx is already owned by another CompositeTranslatorInstance controller my-translator-bbjb4"}

The issue is that the binding controllers sets a service instance as owner reference for the binding CR. Typically, such owner references are set when a higher-level CR is used to create a lower-level CR (e.g. Deployment creates a Replica Set, and sets the ControllerReference in the ReplicaSet ). In the IBM Cloud Operator service case, the binding CR is not created by the service CR, but it has an independent lifecycle as it can be independently created and deleted. Furthermore, even if service CR is deleted, I should be able to point a binding CR to a new service CR if desired.