[3.10] gh-143916: Reject control characters in wsgiref.headers.Headers

[3.10] gh-143916: Reject control characters in wsgiref.headers.Headers

gh-143916: Reject control characters in wsgiref.headers.Headers  (GH-143917)

* 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>
Origin: backport, https://github.com/python/cpython/commit/2f840249550e082dc351743f474ba56da10478d2

Gbp-Pq: Name CVE-2026-0865.patch