Add ESQL result type definitions

[swallez]

Adds the API spec for the JSON output of ES|QL query (other formats cannot be represented here).

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
esql.async_query_delete	⚪	Missing test	Missing test
esql.async_query_get	⚪	Missing test	Missing test
esql.async_query_stop	⚪	Missing test	Missing test
esql.async_query	⚪	Missing test	Missing test
esql.query	⚪	293/293	Missing test

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

[Anaethelion]

LGTM

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
esql.async_query_delete	⚪	Missing test	Missing test
esql.async_query_get	⚪	Missing test	Missing test
esql.async_query_stop	⚪	Missing test	Missing test
esql.async_query	⚪	Missing test	Missing test
esql.query	⚪	293/293	Missing test

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

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
esql.async_query_delete	⚪	Missing test	Missing test
esql.async_query_get	⚪	Missing test	Missing test
esql.async_query_stop	⚪	Missing test	Missing test
esql.async_query	⚪	Missing test	Missing test
esql.query	⚪	293/293	Missing test

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

[l-trotta]

@flobernd @JoshMock @Anaethelion any issue if we backport this to 8.19? I think most of us are still using the old binary result

[flobernd]

Fine for me @l-trotta !

[github-actions]

The backport to 8.19 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-8.19 8.19
# Navigate to the new working tree
cd .worktrees/backport-8.19
# Create a new branch
git switch --create backport-4189-to-8.19
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 e9322d61a98b9204b6a186b2e37444561b0191ad
# Push it to GitHub
git push --set-upstream origin backport-4189-to-8.19
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.19

Then, create a pull request where the base branch is 8.19 and the compare/head branch is backport-4189-to-8.19.