Use unicode DOT OPERATOR instead of MIDDLE DOT in pretty printing

[rikardn]

• Closes Pretty printing using MIDDLE DOT unicode character instead of DOT OPERATOR #2272
• Executed pre-commit run --all-files or pixi run lint --all-files with no errors
• The change is fully covered by automated unit tests
• Documented in docs/ as appropriate
• Added an entry to the CHANGES file

I replaced all instances o the DOT OPERATOR character with MIDDLE DOT in code, documentation and tests.

[codspeed-hq]

Merging this PR will not alter performance

✅ 448 untouched benchmarks

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_{Comparing rikardn:dot_operator (8c93c17) with master (ea5a863)}

[rikardn]

About the doctest fail:

When I grep on the expected string I cannot find it. Where are the doctests specified?

[andrewgsavage]

pint/docs/user/formatting.rst

Line 22 in ea5a863

>>> f"{q:~P}" # short pretty