Bug: If node addition during autoscaling fails, autoscaler does not recognized this

[Despire]

Current Behaviour

Currently if the autoscaling event triggered an addition of a new node into the cluster, and that node fails to be added, autoscaler will think that the node was added successfully.

Expected Behaviour

Autoscaler should only consider the addition of a node to be successful when the node is actually joined to the cluster.

Steps To Reproduce

1. Build a cluster with autoscaled nodepool
2. trigger an addition of a new node
3. intentionally make the addition fail.
4. see that autoscaler will think that the node was added and will not request a new scaleup/scaledown.

[Despire]

Closing this, as I was testing features in #1631 and this issue is related to those features, which will be fixed