ES|QL: add include_execution_metadata to the query spec

[luigidellaquila]

Adding include_execution_metadata parameter to ES|QL query specification.
See elastic/elasticsearch#134446

Closes: #5299

[github-actions]

Following you can find the validation changes against the target branch for the APIs.

No changes detected.

You can validate these APIs yourself by using the make validate target.

[quux00]

LGTM

[l-trotta]

thanks for the contribution @luigidellaquila! considering include_ccs_metadata and include_execution_metadata are synonyms and share the exact same description, I think it makes sense to add include_execution_metadata as an alias of the existing include_ccs_metadata:

...
 * @server_default false
 * @aliases include_execution_metadata
 */
include_ccs_metadata?: boolean

Also, should this be in specification/esql/async_query/AsyncQueryRequest.ts too?

[luigidellaquila]

Thanks for checking @l-trotta
Since from now on we want include_execution_metadata to be the preferred way, do you think it makes sense to do it the other way around, ie. have include_ccs_metadata as an alias for include_execution_metadata? Or is it unusual since include_ccs_metadata was already there?

Or maybe we should keep both with the respective @alias definitions?

[idegtiarenko]

I am not very familiar with this project, but since we have a distinct file for serverless, should the regular one not include include_execution_metadata?

[l-trotta]

if include_execution_metadata has not been marked as only available in stack or serverless, then it will be added to both files

[luigidellaquila]

include_execution_metadata will be available in stateful as well, so I guess it's fine to have a single definition with

 * @availability stack ...
 * @availability serverless

[luigidellaquila]

OK, I went for just adding @aliases to the existing parameters.
@l-trotta in case you want to have another look

[l-trotta]

@luigidellaquila thanks for the changes! I'll just quickly check with the team because I need to make sure this won't be a breaking change when include_ccs_metadata gets removed. LGTM!

[luigidellaquila]

Thanks all! Merging