[3.12] gh-143916: Reject control characters in wsgiref.headers.Headers (GH-143917) (GH-143973) (#143974)

* Add 'test.support' fixture for C0 control characters
* gh-143916: Reject control characters in wsgiref.headers.Headers

(cherry picked from commit f7fceed79ca1bceae8dbe5ba5bc8928564da7211)
(cherry picked from commit 22e4d55285cee52bc4dbe061324e5f30bd4dee58)

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