test: expand benchmarks, use codspeed

[wpbonelli]

Expand the benchmark suite and use codspeed to manage it. Also move the pytest config from a pytest.ini file to pyproject.toml. Close #1989

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 52.9%. Comparing base (556c088) to head (11684fa).
⚠️ Report is 117 commits behind head on develop.

Additional details and impacted files

@@            Coverage Diff             @@
##           develop    #2698     +/-   ##
==========================================
- Coverage     55.5%    52.9%   -2.6%     
==========================================
  Files          644      667     +23     
  Lines       124135   130394   +6259     
==========================================
+ Hits         68947    69036     +89     
- Misses       55188    61358   +6170     

see 495 files with indirect coverage changes

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