[BUG] Support cuDF Scalar Column Views #4291
Description
Describe the bug
This cuDF PR adds scalar_column_view to cuDF and we should support it. Currently scalars are detected by #rows == 1, but this yields incorrect behavior in some jitted column operations, such as filter and transform.
Steps/Code to reproduce bug / Expected behavior
See the cuDF PR for an example failure case.
Additional context
We should modify ColumnVector::fromScalar() to mirror the C++ side once the cuDF PR is merged, returning our own (to be created in cuDF java) ScalarColumnView class. Then we should detect this input in the jni layer where filter/transform is called, and pass cuDF scalar_column_view of our data as needed. We should do this before our currently-used soon-to-be-deprecated functions are removed.