[NL-to-ESQL] add review/correct steps

[pgayvallet]

Part of https://github.com/elastic/kibana-team/issues/1264

At the moment, we're using the correctCommonEsqlMistakes (non-llm) function to fix common syntax mistakes, but it's fairly limited, and does not allow functional validation of the generated query.

The common pattern for LLM-based review is the review/correct chain prompting: after the generation, you ask the model to review the generation and list errors and possible improvements, when you run another prompt asking to correct the first generation based on the review of the second one.

[elasticmachine]

Pinging @elastic/appex-ai-infra (Team:AI Infra)

[pgayvallet]

Note that from various papers (e.g. this one), self-correctness doesn't work very well without external input.

The best approach here could be to perform programmatic validation of the query (ast validation), and then feed the result of the validation to the LLM for correction, instead of just asking it to review its own work without additional insight.