[MM-48542] Removing integration limits (#21282)

* Removing integration limits

* Remove freemium limit test

* Remove test assertion regarding cloud limits

* Remove GetIntegrationsUsage

* Removing integrations usage notifications

* This shouldn't be removed

* Removing client call and websocket event

* Remove old translations

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

model/websocket_message.go

@@ -76,7 +76,6 @@ const (
 	WebsocketEventThreadFollowChanged                 = "thread_follow_changed"
 	WebsocketEventThreadReadChanged                   = "thread_read_changed"
 	WebsocketFirstAdminVisitMarketplaceStatusReceived = "first_admin_visit_marketplace_status_received"
-	WebsocketEventIntegrationsUsageChanged            = "integrations_usage_changed"
 )
 
 type WebSocketMessage interface {