Emit K8S events to the postgresql CR as feedback to the requestor / user (#896)

* Add EventsGetter to KubeClient to enable to sending K8S events

* Add eventRecorder to the controller, initialize it and hand it down to cluster via its constructor to enable it to emit events this way

* Add first set of events which then go to the postgresql custom resource the user interacts with to provide some feedback

* Add right to "create" events to operator cluster role

* Adapt cluster tests to new function sigurature with eventRecord (via NewFakeRecorder)

* Get a proper reference before sending events to a resource

Co-authored-by: Christian Rohmann <christian.rohmann@inovex.de>

pkg/util/k8sutil/k8sutil.go

@@ -45,6 +45,7 @@ type KubernetesClient struct {
 	corev1.NodesGetter
 	corev1.NamespacesGetter
 	corev1.ServiceAccountsGetter
+	corev1.EventsGetter
 	appsv1.StatefulSetsGetter
 	appsv1.DeploymentsGetter
 	rbacv1.RoleBindingsGetter
@@ -142,6 +143,7 @@ func NewFromConfig(cfg *rest.Config) (KubernetesClient, error) {
 	kubeClient.RESTClient = client.CoreV1().RESTClient()
 	kubeClient.RoleBindingsGetter = client.RbacV1()
 	kubeClient.CronJobsGetter = client.BatchV1beta1()
+	kubeClient.EventsGetter = client.CoreV1()
 
 	apiextClient, err := apiextclient.NewForConfig(cfg)
 	if err != nil {