## What changes were proposed in this pull request?
A GROUPED_AGG pandas python udf can't work, if without group by clause, like `select udf(id) from table`.
This doesn't match with aggregate function like sum, count..., and also dataset API like `df.agg(udf(df['id']))`.
When we parse a udf (or an aggregate function) like that from SQL syntax, it is known as a function in a project. `GlobalAggregates` rule in analysis makes such project as aggregate, by looking for aggregate expressions. At the moment, we should also look for GROUPED_AGG pandas python udf.
## How was this patch tested?
Added tests.
Closes#25352 from viirya/SPARK-28422.
Authored-by: Liang-Chi Hsieh <viirya@gmail.com>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
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