PLT-6080 moving clustering to memberlist (#6499)

* PLT-6080 adding cluster discovery service

* Adding memberlist lib

* Adding memberlist lib

* WIP

* WIP

* WIP

* WIP

* Rolling back config changes

* Fixing make file

* Fixing config for cluster

* WIP

* Fixing system console for clustering

* Fixing default config

* Fixing config

* Fixing system console for clustering

* Tweaking hub setting

* Bumping up time

* merging vendor dir

* Updating vendor dir

* Fixing unit test

* Fixing bad merge

* Remove some testing code

* Moving comment

* PLT-6868 adding db ping retry

* Removing unused loc strings

* Adding defer to cancel

app/session.go

@@ -101,7 +101,12 @@ func ClearSessionCacheForUser(userId string) {
 	ClearSessionCacheForUserSkipClusterSend(userId)
 
 	if einterfaces.GetClusterInterface() != nil {
-		einterfaces.GetClusterInterface().ClearSessionCacheForUser(userId)
+		msg := &model.ClusterMessage{
+			Event:    model.CLUSTER_EVENT_CLEAR_SESSION_CACHE_FOR_USER,
+			SendType: model.CLUSTER_SEND_BEST_EFFORT,
+			Data:     userId,
+		}
+		einterfaces.GetClusterInterface().SendClusterMessage(msg)
 	}
 }