Kubernetes Metric Set Support Capturing VerticalPodAutoscaler Recommendations

**Describe the enhancement:**

VerticalPodAutoscaler (VPA) in recommendation mode makes it easy to determine what you should possibly set Kubernetes resources requests/limits to. It would be nice to be able to collect these recommendations into Elastic

**Describe a specific use case for the enhancement or feature:**

I want to track historical recommendations of pods/containers based on VPA's actions.

No file or test is named in the issue. Start by locating the Kubernetes metricset entry points and how Kubernetes resource metrics are collected; define completion as storing historical VerticalPodAutoscaler recommendations for pods and containers in Elastic, with tests covering the new metric data.

Written by the indexing model from the issue text.