Implement Isolation

[mjudeikis]

Currently backend has this in the API:

// Isolation is an enum defining the different ways to isolate cluster scoped objects
//
// +kubebuilder:validation:Enum=Prefixed;Namespaced;None
type Isolation string

const (
	// Prepends the name of the cluster namespace to an object's name.
	IsolationPrefixed Isolation = "Prefixed"

	// Maps a consumer side object into a namespaced object inside the corresponding cluster namespace.
	IsolationNamespaced Isolation = "Namespaced"

	// Used for the case of a dedicated provider where isolation is not necessary.
	IsolationNone Isolation = "None"
)

But in reality, IsolationPrefixed is only an implementation.
We should implement Namespaced and None.

[xrstf]

I'll take a stab at this.