Re: remaining sql/json patches

based on v35.
Now I only applied from 0001 to 0007.
For {DEFAULT expression ON EMPTY} | {DEFAULT expression ON ERROR}
restrict DEFAULT expression be either Const node or FuncExpr node.
so these 3 SQL/JSON functions can be used in the btree expression index.

I made some big changes on the doc. (see attachment)
list (json_query, json_exists, json_value) as a new <section2> may be
a good idea.

follow these two links, we can see the difference.
only apply v35, 0001 to 0007: https://v35-functions-json-html.vercel.app
apply v35, 0001 to 0007 plus my changes:
https://html-starter-seven-pied.vercel.app

minor issues:
+ Note that if the <replaceable>path_expression</replaceable>
+ is <literal>strict</literal>, an error is generated if it yields no
+ items, provided the specified <literal>ON ERROR</literal> behavior is
+ <literal>ERROR</literal>.

how about something like this:
+ Note that if the <replaceable>path_expression</replaceable>
+ is <literal>strict</literal> and <literal>ON ERROR</literal>
behavior is specified
+ <literal>ERROR</literal>, an error is generated if it yields no
+ items

+ <note>
+ <para>
+ SQL/JSON path expression can currently only accept values of the
+ <type>jsonb</type> type, so it might be necessary to cast the
+ <replaceable>context_item</replaceable> argument of these functions to
+ <type>jsonb</type>.
+ </para>
+ </note>
here should it be "SQL/JSON query functions"?