Fix pint-0.20 support and fix test warnings

[marscher]

Changes

• Urgent fix for pint-0.20, which renamed the classes Unit and Quantity.
• Fixed several warnings during testing

Related Issues

Closes #819

Checks

• [x] updated CHANGELOG.rst
• [x] updated tests

TODO

Sphinx errors/warnings

• [ ] Cannot resolve forward reference in type annotations of "weldx.U_": name 'Unit' is not defined
• [ ] docstring of weldx.ArcSegment.arc_angle:1: WARNING: py:class reference target not found: pint.Quantity

[CagtayFabry]

thank you for looking into this so quickly!

[github-actions[bot]]

Test Results

2 185 tests  ±0   2 184 :heavy_check_mark: ±0   2m 34s :stopwatch: -2s        1 suites ±0          1 :zzz: ±0         1 files   ±0          0 :x: ±0 

Results for commit dd5c3f5b. ± Comparison against base commit d30fa8ed.

[codecov[bot]]

Codecov Report

Merging #818 (dd5c3f5) into master (d30fa8e) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #818   +/-   ##
=======================================
  Coverage   96.80%   96.80%           
=======================================
  Files          81       81           
  Lines        5380     5380           
=======================================
  Hits         5208     5208           
  Misses        172      172           

Impacted Files	Coverage Δ
weldx/tags/units/pint_quantity.py	97.29% <ø> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

[WilliamJamieson]

As part of asdf-format/asdf#1217, we decided we needed to run ASDF's downstream tests, on of which is for weldx. We see failures as part of that CI: https://github.com/asdf-format/asdf/actions/runs/3330072266/jobs/5508084188.

It looks like these failures are being fixed by this PR. Is this correct, or is the proposed ASDF causing other failures?

I suspect, its an issue with changes around weldx as the latest downstream chron: https://github.com/asdf-format/asdf/actions/runs/3310625674/jobs/5465066153 passed, but now it doesn't https://github.com/asdf-format/asdf/actions/runs/3330156118/jobs/5508275836. However, no changes have been made to ASDF between the two runs.

[marscher]

@WilliamJamieson the test issues are due to refactorings in the Pint package. The Quantity type is not being being captured by the Converter type list. This will be fixed by this PR.

[marscher]

@CagtayFabry I'm going to merge this now. Pint did some refactoring on the documentation, and the intersphinx mapping will be most likely different (e.g. pint.Quantity will be in pint.util.Quantity). I will open up a follow up PR for this.