Plugin discovery data from PluginProvider.provideDiscoveryData should be available in PluginProvider.validateNewNode

Current  sequence:
 
1)Server starts (coordinator)
2)Client starts
3)Client sends to the coordinator its discovery data using provideDiscoveryData method
4)Coordinator start validation of the node using validateNewNode
5)The client joins the cluster; otherwise fails
6)Coordinator provides the discovery data to plugin provider in receiveDiscoveryData. After that this data could be passed to the plugin.

But in case if we require to validate new node using the discovery data from receiveDiscoveryData method then we should add a possibility to get this data in validateNewNode method.