(split out from #31280)

As noted in #31280 comment:65, this helps
for #30768 and hence for Python 3.10 compatibility.

Three packages are added, each becoming
a standard spkg.

charset-normalizer

Added under the name charset_normalizer.

"Charset Detection, for Everyone"

A library that helps you read text from an unknown
charset encoding.

[...] All IANA character set names for which the
Python core library provides codecs are supported.

idna

Support for the Internationalised Domain Names
in Applications (IDNA) protocol as specified
in RFC 5891. This is the latest version of the
protocol and is sometimes referred to as “IDNA 2008”.

This library also provides support
for Unicode Technical Standard 46,
Unicode IDNA Compatibility Processing.

This acts as a suitable replacement for the
“encodings.idna” module that comes with the
Python standard library, but which only supports
the old, deprecated IDNA specification (RFC 3490).

urllib3

a powerful, user-friendly HTTP client for Python.
[...]
urllib3 brings many critical features that are
missing from the Python standard libraries:

• Thread safety.
• Connection pooling.
• Client-side SSL/TLS verification.
• File uploads with multipart encoding.
• Helpers for retrying requests and dealing with HTTP redirects.
• Support for gzip, deflate, and brotli encoding.
• Proxy support for HTTP and SOCKS.
• 100% test coverage.

CC: @fchapoton @slel @dimpase

Component: packages: standard

Author: Matthias Koeppe

Branch/Commit: 8cc62de

Reviewer: Dima Pasechnik

Issue created by migration from https://trac.sagemath.org/ticket/32372