jubaclassify UDF

[nobu-k]

Providing only one classification UDF is fine. For example, provide jubaclassify which uses a shared state implementing classifier.Classifier interface. The UDF doesn't have to know which algorithm the state implements. The state only has to satisfy the interface so that each classification algorithm doesn't need to have its own classification function.

Then, remove jubaclassifier_arow_classify UDF.