Use authentication error message from response body

[electrum]

Description

All versions of Trino (since c0bcc9b) send the error message in the response body. The reason phrase does not exist in HTTP/2.

Release notes

(x) Release notes are required, with the following suggested text:

# CLI
* Improve authentication error messages when accessing the server over HTTP/2. ({issue}`15720`)

# JDBC driver
* Improve authentication error messages when accessing the server over HTTP/2. ({issue}`15720`)

[electrum]

This is required by #15703 since the Jetty 10 server no longer sends the provided reason phrase (at least via the servlet APIs used by our version of Jersey).

[colebow]

I think we can skip release notes for this. It's generally been the practice that if users will encounter better messaging, that messaging is self-documenting when it's encountered, and it doesn't really do them much good to know that the messaging will be better.