Trait that all the messages that should be received from a ClusterListener must implement.
A DatabaseAddedMessage is used to tell to the SettingsManager that there is a new database.
A DatabaseAddedMessage is used to tell to the SettingsManager that a database has been removed.
A RoundRobinAddressMessage is used to ask to a RoundRobinAddresses the address to choose to deploy an actor.
A SettingsUpdatedMessage is used to tell to the SettingsManager that the settings has been updated.
ClusterListenerMessages are the messages that ClusterListener receives for future implementations.