Make OwnedByHelmRelease default to true

To work around an edge case scenarios some users have reported where
the release manifest does not result in any resources (or they are
all skipped), and the `HelmRelease` is therefore falsely marked as
'not being owned by'.

This should all be refactored to an `ownerReference`, so that we can
make use of Kubernetes' garbage collection functionalities[1] and no
longer reinvent the wheel.

[1]: https://kubernetes.io/docs/concepts/workloads/controllers/garbage-collection/#owners-and-dependents

pkg/release/release.go

@@ -344,7 +344,7 @@ func (r *Release) OwnedByHelmRelease(release *hapi_release.Release, hr helmfluxv
 		}
 	}
 
-	return false
+	return true
 }
 
 // annotateResources annotates each of the resources created (or updated)