Make better use of ParseState in ProcessUtility

Make better use of ParseState in ProcessUtility

Pass ParseState into the functions called from
standard_ProcessUtility() instead passing the query string and query
environment separately.  No functionality change, but it makes the
notation consistent.  We had already started moving things into
that direction piece by piece, and this completes it.

Reviewed-by: Pavel Stehule <pavel.stehule@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/6e7aa4a1-be6a-1a75-b1f9-83a678e5184a@2ndquadrant.com