bpo-44242: [Enum] improve error messages (GH-26669)

(cherry picked from commit c956734d7af83ad31f847d31d0d26df087add9a4)

Co-authored-by: Ethan Furman <ethan@stoneleaf.us>

Co-authored-by: Ethan Furman <ethan@stoneleaf.us>
2 files changed