ci: Add tests for serialization and printing of dy.Enum columns

[MoritzPotthoffQC]

Merge after #150

Motivation

The possible values are now stored as pl.Series (#138), which can't be json-serialized and break repr as the check against the default argument now produces a series object (element-wise comparison) which can't be evaluated as boolean. This means that in these methods, we always treat categories as list (even when they are actually a pl.Series). I am not sure if this has any undesired effects.

Changes

• Convert the values to a python list before serialization and evaluation in __repr__
• Extended tests

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (56b2f86) to head (bb4fc17).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main      #147   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           50        50           
  Lines         2851      2841   -10     
=========================================
- Hits          2851      2841   -10     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[MoritzPotthoffQC]

@borchero @AndreasAlbertQC this fixes the current state, but is maybe also an extra argument for this approach. Up to you how we fix it. I am also not sure whether there are any other similar issues left that we did not run into yet.

[borchero]

This is the second issue that we've run into after using Series instead of list here, let's please store the categories as list 😅 fyi @AndreasAlbertQC

EDIT: Sorry, didn't see your additional comment @MoritzPotthoffQC, I agree

[AndreasAlbertQC]

Could not agree more

[AndreasAlbertQC]

This PR is now based on #150, which fixes the underlying problems. I still want to merge this PR to get the tests.