Re: SQL:2023 JSON simplified accessor support

Hi Alex,

The code comments and the commit messages help a lot when reviewing! Thanks for
the new version.

The code LGTM and check-world is happy. I've also performed some tests and
everything looks good!

Just some minor points about this new version:

## v9-0005

Typo on commit message title

## v9-0006

> + * The following functions create various types of JsonPathParseItem nodes,
> + * which are used to build JsonPath expressions for jsonb simplified accessor.
>
Just to avoid misinterpretation I think that we can replace "The following
functions" with "The make_jsonpath_item_* functions" since we can have more
functions in the future that are not fully related with these. Does that make
sense?

-- 
Matheus Alcantara