Handle parsing of bare sequence yaml nodes

[phanimarupaka]

kyaml uses reader annotations to track resources for reading and writing back, it is not possible to add reader annotations to bare sequence nodes, this PR introduces a way to wrap/unwrap such nodes for smooth yaml processing.

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[natasha41575]

/cc @KnVerey

[natasha41575]

/lgtm

[droot]

Mostly looking good, have a few comments.

[KnVerey]

Could you provide an example to illustrate in what contexts this is needed? How could a resource be a bare sequence node?

[phanimarupaka]

Could you provide an example to illustrate in what contexts this is needed? How could a resource be a bare sequence node?

Here is an example valid YAML node(Kustomization patch) https://github.com/kubeflow/manifests/blob/master/apps/jupyter/notebook-controller/upstream/crd/patches/old_crd.yaml

[KnVerey]

Thanks! I still don't quite understand the use case though--the description says "kyaml uses reader annotations to track resources for reading and writing back" and that inability to annotate bare sequence nodes is a problem, but your example is a JSON patch not a resource. What reader annotations do you need to apply to a patch like that?