First compilable state with go-client 6.0

There are shortcuts in this code, i.e. we created the deepcopy function
by using the deepcopy package instead of the generated code, that will
be addressed once migrated to client-go v8. Also, some objects,
particularly statefulsets, are still taken from v1beta, this will also
be addressed in further commits once the changes are stabilized.

pkg/controller/postgresql.go

@@ -147,12 +147,12 @@ func (d *crdDecoder) Decode() (action watch.EventType, object runtime.Object, er
 
 func (c *Controller) clusterWatchFunc(options metav1.ListOptions) (watch.Interface, error) {
 	options.Watch = true
+	// MIGRATION: FieldsSelectorParam(nil)
 	r, err := c.KubeClient.CRDREST.
 		Get().
 		Namespace(c.opConfig.WatchedNamespace).
 		Resource(constants.PostgresCRDResource).
 		VersionedParams(&options, metav1.ParameterCodec).
-		FieldsSelectorParam(nil).
 		Stream()
 
 	if err != nil {