Issue 841. Schedule for cluster node. Part 1

[SilinPavel]

This PR add new type of scheduling event: CLUSTER_NODE_SCALE
Now ClusterController has new batch of CRUD methods for manipulating of CLUSTER_NODE_SCALE events.
By adding new schedule for event new job ClusterNodeScaleJob will be created.
This job will simply put to a special queue ClusterNodeScaleAction object that contains the next entry:

ClusterNodeScale clusterNodeScale
RunScheduledAction action
String user

For the next part of implementation proposing use this queue to fetch actions in AutoscaleManager and scale up or scale down a cluster