Support endpoints and request types in openapi_to_clients_schema

[pquentin]

🚀 Feature Proposal

https://github.com/elastic/elasticsearch-specification/tree/main/compiler-rs/openapi_to_clients_schema is an experiment to generate a schema.json file from an OpenAPI specification. It was abandoned when we realized that doing this is not possible in general. But if we target the Kibana OpenAPI specification in particular, this is much more tractable.

We should support endpoints and request types in order to generate a simple schema.json for the Kibana SystemStatus API.

Motivation

This can be a building block to eventually get Kibana language clients:

from elasticsearch import Kibana

client = Kibana(
    hosts="http://localhost:5601",
    api_key="...",
)
resp = client.system_status()
assert resp.body["status"]["overall"]["level"] == "available"