Consider migrating to apache arrow as backend

[holgerbrandl]

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See https://arrow.apache.org/docs/java/

[Kopilov]

Hi @holgerbrandl I am going to make Krangl<->Arrow conversion for my customer's project, later in can be embedded to Krangl

[holgerbrandl]

Thanks for sharing. I plan to migrate krangl to use https://github.com/Kotlin/dataframe as backend soon, while preserving most of its additional functionality. In the near future I envision krangl more as a support API on top of kotlin-dataframe. So maybe you could also consider to add arrow support to https://github.com/Kotlin/dataframe instead (fyi @nikitinas)