FeatureStore._plan should be a public method #2895

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https://github.com/feast-dev/feast/blob/master/sdk/python/feast/feature_store.py#L639

Ideally, all FeatureStore methods that back a CLI operation should have a public facing programatic API. In this case, feast plan users FeatureStore._plan -> which signifies that it should be treated as a private method.

Describe the solution you'd like
The change would be as simple as refactoring it to FeatureStore.plan.