[3.9] bpo-45083: Include the exception class qualname when formatting an exception...

[3.9] bpo-45083: Include the exception class qualname when formatting an exception (GH-28119) (GH-28135)

* bpo-45083: Include the exception class qualname when formatting an exception (GH-28119)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>
(cherry picked from commit b4b6342848ec0459182a992151099252434cc619)

Co-authored-by: Irit Katriel <1055913+iritkatriel@users.noreply.github.com>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>