[3.9] gh-122792: Make IPv4-mapped IPv6 address properties consistent with IPv4 (GH-122793) (GH-123819) (GH-127571)

Make IPv4-mapped IPv6 address properties consistent with IPv4.
(cherry picked from commit 76a1c5d18312712baed4699fe7333abb050ec9b7)
(cherry picked from commit b58da409aac90123c1159916908a4c49144925ee)

Co-authored-by: Seth Michael Larson <seth@python.org>

• Lib/ipaddress.py[diff]
• Lib/test/test_ipaddress.py[diff]
• Misc/NEWS.d/next/Security/2024-08-07-10-42-13.gh-issue-122792.oiTMo9.rst[Added - diff]