[3.10] bpo-46648: Rewrite test_urllib2.test_issue16464() with a local HTTP server (GH-31186) (GH-31189)

Re-enable test_issue16464() of test_urllib2, move it to urllib2_localnet
and use the local HTTP server rather than an external HTTP server.
(cherry picked from commit 8e98175a03fe03d62822d96007a74e5273013764)


Co-authored-by: Nikita Sobolev <mail@sobolevn.me>