SMTP failure response codes are saved in the Bounce record

Instead of translating bounce codes, the original SMTP response text is saved to civicrm_mailing_event_bounce.bounce_reason

An improvement on this patch would be to add another column to hold this raw data, and expose a column visibility checkbox in the Bounce Report.
I also introduced a workaround, shortening a Civi error message generated in packages/Net/SMTP rather than resize the current column.