[Data] Cosmetic changes to Arrow Tensor __repr__

[pcmoritz]

Why are these changes needed?

Make it clear what the data type actually is -- a numpy array. Also make the argument ordering consistent between the two types.

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[amogkam]

awesome, thanks!

[ericl]

I think the tests look ok, but probably should rebase and try again to be sure. A lot are failing with some core build error.

[pcmoritz]

Yeah, I was planning to wait merging this until the docs build is green again on master to make sure there is not more breakage introduced by this. Let me look into what still needs to be fixed for the doc build :)