[BUG] update_by_query and delete_by_query parameters are incorrect

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What is the bug?

Trying to use _source with update_by_query and delete_by_query seems to have no effect as either an array of strings (as defined) or a boolean. Cannot get _source to return. Either the documentation is incorrect (https://opensearch.org/docs/latest/api-reference/document-apis/delete-by-query/) or the spec is incorrect or OpenSearch has a bug or is missing a feature.

How can one reproduce the bug?

Add _source to tests/default/indices/update_by_query.yaml and/or tests/default/indices/delete_by_query.yaml.

What is the expected behavior?

Match spec to what's in the OpenSearch code.

Do you have any additional context?

I added tests in https://github.com/opensearch-project/opensearch-api-specification/pull/547.