Change drag-and-drop behavior in notebooks for new CSV

[Jolanrensen]

should be changed for next release

[zaleslaw]

Could you please share more ideas/details there and I will move this ticket in YouTrack

[Jolanrensen]

I mean, we should simply rename readCSV -> readCsv, readTSV -> readTsv, the rest should work exactly the same.
But only when we have a release with this as the default CSV implementation of course.