[3.12] gh-123067: Fix quadratic complexity in parsing "-quoted cookie values with backslashes (GH-123075) (#123104)

gh-123067: Fix quadratic complexity in parsing "-quoted cookie values with backslashes (GH-123075)

This fixes CVE-2024-7592.
(cherry picked from commit 44e458357fca05ca0ae2658d62c8c595b048b5ef)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>