gh-66897: Upgrade HTTP CONNECT to protocol HTTP/1.1 (#8305)

* bpo-22708: Upgrade HTTP CONNECT to protocol HTTP/1.1 (GH-NNNN)

Use protocol HTTP/1.1 when sending HTTP CONNECT tunnelling requests;
generate Host: headers if one is not already provided (required by
HTTP/1.1), convert IDN domains to punycode in HTTP CONNECT requests.

* Refactor tests to pass under -bb (fix ByteWarnings); missed some lines >80.

* Use consistent 'tunnelling' spelling in Lib/http/client.py

* Lib/test/test_httplib: Remove remnant of obsoleted test.

* Use dict.copy() not copy.copy()

* fix version changed

* Update Lib/http/client.py

Co-authored-by: bgehman <bgehman@users.noreply.github.com>

* Switch to for/else: syntax, as suggested

* Don't use for: else:

* Sure, fine, w/e

* Oops

* 1nm to the left

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Co-authored-by: Éric <merwok@netwok.org>
Co-authored-by: bgehman <bgehman@users.noreply.github.com>
Co-authored-by: Oleg Iarygin <oleg@arhadthedev.net>