Merge 3.6.2 into master (#5211)

* Add webhook cache

* Add channel by name cache

* Fxing profiles in channels cache

* Fix merge

einterfaces/cluster.go

@@ -15,7 +15,10 @@ type ClusterInterface interface {
 	ClearSessionCacheForUser(userId string)
 	InvalidateCacheForUser(userId string)
 	InvalidateCacheForChannel(channelId string)
+	InvalidateCacheForChannelByName(teamId, name string)
+	InvalidateCacheForChannelMembers(channelId string)
 	InvalidateCacheForChannelPosts(channelId string)
+	InvalidateCacheForWebhook(webhookId string)
 	Publish(event *model.WebSocketEvent)
 	UpdateStatus(status *model.Status)
 	GetLogs() ([]string, *model.AppError)