Feat/timeseries improvements

[dennisbader]

Checklist before merging this PR:

• Mentioned all issues that this PR fixes or addresses.
• Summarized the updates of this PR under Summary.
• Added an entry under Unreleased in the Changelog.

Summary

• TimeSeries.from_dataframe() now supports time columns of type pl.Date for polars.DataFrame.
• Fixed a bug in TimeSeries.quantile() where the output dtype did not match the input series dtype for dtypes float32 or float16. Now the dtype is correctly propagated.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.47%. Comparing base (40af46d) to head (2a7822d).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #3124      +/-   ##
==========================================
- Coverage   96.54%   96.47%   -0.07%     
==========================================
  Files         160      160              
  Lines       17261    17262       +1     
==========================================
- Hits        16664    16654      -10     
- Misses        597      608      +11     

☔ 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.