Connection pooler for replica (#1127)

* Enable connection pooler for replica
* Refactor code for connection pooler
  - Move all the relevant code to a separate file
  - Move all the related tests to a separate file
  - Avoid using cluster where not required
  - Simplify the logic in sync and other methods
  - Cleanup of duplicated or unused code
* Fix labels for the replica pods
* Update deleteConnectionPooler to include role
* Adding test cases and other changes
   - Fix unit test and delete secret when required only
   - Make sure we use empty fresh cluster for every test case.
* enhance e2e test
* Disable pooler in complete manifest as this is source for e2e too an creates unnecessary pooler setups.

Co-authored-by: Rafia Sabih <rafia.sabih@zalando.de>
Co-authored-by: Jan Mussler <janm81@gmail.com>

pkg/controller/postgresql.go

@@ -473,7 +473,7 @@ func (c *Controller) queueClusterEvent(informerOldSpec, informerNewSpec *acidv1.
 	if err := c.clusterEventQueues[workerID].Add(clusterEvent); err != nil {
 		lg.Errorf("error while queueing cluster event: %v", clusterEvent)
 	}
-	lg.Infof("%q event has been queued", eventType)
+	lg.Infof("%s event has been queued", eventType)
 
 	if eventType != EventDelete {
 		return
@@ -494,7 +494,7 @@ func (c *Controller) queueClusterEvent(informerOldSpec, informerNewSpec *acidv1.
 		if err != nil {
 			lg.Warningf("could not delete event from the queue: %v", err)
 		} else {
-			lg.Debugf("event %q has been discarded for the cluster", evType)
+			lg.Debugf("event %s has been discarded for the cluster", evType)
 		}
 	}
 }