MIGRATE: pandas_panel lecture from stats

[mmcky]

This PR migrates pandas_panel from lecture-stats

fixes #303

[github-actions]

🚀 Deployed on https://663185f000a82f4086889c1f--epic-agnesi-957267.netlify.app

[mmcky]

There are a few deprecation notices that should be addressed

• fix dataframe deprecation

FutureWarning: DataFrame.groupby with axis=1 is deprecated. Do `frame.T.groupby(...)` without axis instead.
  merged.groupby(level='Continent', axis=1).mean().head()

• fix seaborn deprecation

/home/runner/miniconda3/envs/quantecon/lib/python3.11/site-packages/seaborn/_oldcore.py:1119: FutureWarning: use_inf_as_na option is deprecated and will be removed in a future version. Convert inf values to NaN before operating instead.

[mmcky]

@jstac are you happy for this to be merged.

The main changes to the incoming lecture are captured in caaacae

[jstac]

Thanks @mmcky . I'm a little busy but perhaps @shlff could provide a second set of eyes?

I'll leave you to merge when ready.

[mmcky]

Thanks @shlff the only real changes being applied are to fix deprecation notices in pandas in caaacae otherwise this is just migrating the lecture from it's old location.

[shlff]

I see. Thanks @mmcky .

I quickly went through the lecture:

• the two depreciation notices have been fixed, and
• all links are working well.

This lecture looks good to me so I reckon it is ready to be merged.

[mmcky]

thanks @shlff -- greatly appreciate the second set of eyes.