Fix bug 2413 NPE for group and meters

Fix bug 2413 NPE for group and meters

* group/meter features
	* Device RPC features Calls for group/meter depend on FlowCapableNode data change event (create event only)
	* Remove Meter's and Group's feature calls from perm. stat. collect
	* Add API methods for additional registration new StatCapabTypes for a specific Node statistic collecting process
	* Fix NPE for features
* refactoring group/meter stats update processing (Target: Don't block the RPC Notification threads as soon as is possible)
	* Fix NPE List processing
* queue - add delete processing (becasue queues has to be edit outside and we are not cleaning it)
* add validations input values
* remove unnecessary validation input values (StatRpcMsgManagerImpl)

Signed-off-by: Vaclav Demcak <vdemcak@cisco.com>
Change-Id: If10a0ea0bb098ca70cd19ce32a7ca5790159aae5