TransportMasterNodeAction unnecessarily captures complete cluster state

[DaveCTurner]

Today TransportMasterNodeAction$AsyncSingleAction#doStart captures a reference to the clusterState in a couple of listeners that might get used if it needs to use a ClusterStateObserver to retry the action. Yet, both ClusterStateObserver and MasterNodeChangePredicate each need just a handful of fields from the whole cluster state. If we made these things more eagerly then there would be no need to capture the whole state for each master node action.

[elasticsearchmachine]

Pinging @elastic/es-distributed (Team:Distributed)