Manual backport of two PRs: * #125155 * #125251
Even though the docs are not needed in 9.0, due to all docs being
published off main, doing the backport makes future backports of
non-docs, but docs-adjacent PRs easier.
This entirely syncs the contents of docs/reference/query-languages/esql with main, just so we can continue auto-backporting easily, which will continue to be relevant.
