kube_pool_cpu is oriented to .com deployments where all services have dedicated node pools, epitomised by the "appliesTo" expression of "metricsCatalog.findKubeProvisionedServicesWithDedicatedNodePool".  This is not useful for GET CNH deploys which have multi-use node groups (do not always have Dedicated Node Pools).

Additionally, GET metrics do not necessarily have the "node" label, so the use of node_cpu_seconds_total:labeled is not feasible to get a type-labelled metric.  However, Dedicated (the main user of GET CNH metrics catalog) scrapes node metrics with a "type" label that records the node group name, in a format ending in "pool".  Therefore this adds:

1. A "kube" service for get-hybrid, copied from the .com equivalent.  Includes the apiserver SLI just because it seems plausibly interesting.
2. A new node_group_cpu saturation metric based on the GET/Dedicated labelling scheme, and for all node groups even running mixed workl...