Addressed issue titled "HDI naming" by changing the lower and upper hdi bound names in stats.py summary() function to hdi_{hdi_prob}_lb and hdi_{hdi_prob}_ub

[YunwooC]

Description

Addresed issue titled "HDI naming", ID: #2306. Improved naming for lower and higher hdi bounds in stats.py summary() function by renaming them to hdi_{hdi_prob}_ lb and hdi_{hdi_prob}_ ub.

Checklist

• Follows official PR format
• Code style correct (follows pylint and black guidelines)

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📚 Documentation preview 📚: https://arviz--2454.org.readthedocs.build/en/2454/

[aloctavodia]

Thanks @YunwooC!

I understand your contribution follows the discussion in #2306. I just want to mention that in ArviZ-stats, I used a different solution. We can use either one, just mentioning it so we unify them.

[OriolAbril]

Agreed with @aloctavodia that it would be best to match arviz-stats. Also, note that the PR adds the _l/ub part between the probability and the % sign:

so it can't be merged as is even if matching arviz-stats weren't an issue