[3.8] [CVE-2023-27043] gh-102988: Reject malformed addresses in email.parseaddr() (GH-111116) (#123770)

Detect email address parsing errors and return empty tuple to
indicate the parsing error (old API). Add an optional 'strict'
parameter to getaddresses() and parseaddr() functions. Patch by
Thomas Dwyer.

(cherry picked from commit 4a153a1d3b18803a684cd1bcc2cdf3ede3dbae19)

Co-authored-by: Victor Stinner <vstinner@python.org>
Co-Authored-By: Thomas Dwyer <github@tomd.tel>

• Doc/library/email.utils.rst[diff]
• Doc/whatsnew/3.8.rst[diff]
• Lib/email/utils.py[diff]
• Lib/test/test_email/test_email.py[diff]
• Misc/NEWS.d/next/Library/2023-10-20-15-28-08.gh-issue-102988.dStNO7.rst[Added - diff]