Create ClusterSpec in the cluster controller to send to cluster provider reconciler

**What would you like to be added**:
Build and send clusterSpec for clusterProviderReconciler.ReconcileWorkerNodes and clusterProviderReconciler.Reconcile

**Why is this needed**:
Cluster Spec is built at each provider reconciler level, instead we can build it once in the cluster controller.

Locate the cluster controller and the clusterProviderReconciler.ReconcileWorkerNodes and Reconcile entry points. Read how each provider reconciler currently builds its ClusterSpec, then trace the data passed from the controller. Done means the controller builds ClusterSpec once and sends it to both reconciler paths.

Written by the indexing model from the issue text.