Fixed #36467 -- Removed leading whitespaces from Set-Cookie header values in WSGIHandler.

This also aligned the Set-Cookie logic in the WSGIHandler and ASGIHandler.

Co-authored-by: Sarah Boyce <42296566+sarahboyce@users.noreply.github.com>

tests/wsgi/urls.py

@@ -6,7 +6,14 @@ def helloworld(request):
     return HttpResponse("Hello World!")
 
 
+def cookie(request):
+    response = HttpResponse("Hello World!")
+    response.set_cookie("key", "value")
+    return response
+
+
 urlpatterns = [
     path("", helloworld),
+    path("cookie/", cookie),
     path("file/", lambda x: FileResponse(open(__file__, "rb"))),
 ]