BUG: groupby.agg with UDF changing pyarrow dtypes

[rhshadrach]

Continuation of #58129

• closes BUG: Groupby-aggregate on a boolean column returns a different datatype with pyarrow than with numpy #53030 (Replace xxxx with the GitHub issue number)
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations to new arguments/methods/functions.
• Added an entry in the latest doc/source/whatsnew/vX.X.X.rst file if fixing a bug or adding a new feature.

Root cause:

• agg_series always forces output dtype to be the same as input dtype, but depending on the lambda, the output dtype can be different

Fix:

• replace all NA with nan
• convert the `results' to respective pyarrow extension array, using pyarrow library methods
• pyarrow library methods is used instead of maybe_convert_object, as maybe_convert_object does not check for NA, and forces dtype to float if NA is present (NA is not float in pyarrow),

[github-actions]

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