I've updated the listener for GET /_query/async/{id} to EsqlResponseListener, so it now accepts parameters (delimiter, drop_null_columns and format) like the POST /_query API. Additionally, I have added tests to verify the correctness of the code.
You can now set the format in the request parameters to specify the return style.
Closes#110926
This commit adds detailed API docs for the ES|QL async apis, as well as moving the narrative to the ES|QL specific REST docs. Additionally, a few top-level lists are reflowed to reflect that there are now multiple APIs.