[META][Kubernetes provider/Kubernetes module] Set watcher options node based on configuration

[constanca-m]

We need to do similar work for node as we did for namespace in this issue.

• [ ] [Beats] In beats, check node option is being taken into consideration. For example, the watcher is not using the node option for deployment: https://github.com/elastic/beats/blob/269d31935ea6a107cfdc8d9317aff78cb5d7263f/libbeat/autodiscover/providers/kubernetes/pod.go#L128-L133
• [ ] [Beats] Check add_kubernetes_metadata node option as well
• [ ] [Beats] Update documentation
• [ ] [Elastic Agent] Check the Kubernetes provider uses the node option
• [ ] [Integrations] Put the node option at group level, similar as we did for namespace here.

[botelastic[bot]]

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