[3.12] gh-116764: Fix regressions in urllib.parse.parse_qsl() (GH-116801) (GH-116894)

* Restore support of None and other false values.
* Raise TypeError for non-zero integers and non-empty sequences.

The regressions were introduced in gh-74668
(bdba8ef42b15e651dc23374a08143cc2b4c4657d).
(cherry picked from commit 1069a462f611f0b70b6eec0bba603d618a0378f3)

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