Is your feature request related to a problem or challenge? Please describe what you are trying to do.

Currently binary arrays are defined as GenericByteArray<i32> and GenericByteArray<i64>, and string arrays as GenericStringArray<i32> and GenericStringArray<i64>.

There are a couple of issues with this:

• It is isn't possible to write kernels that are generic over both, despite them having identical layout
• The type signature of these is inconsistent with PrimitiveArray which makes use of a sentinel type struct

Describe the solution you'd like

I would like a new GenericBinaryArray<T: BinaryArrayType> which GenericByteArray and GenericStringArray are defined as type aliases of.

Describe alternatives you've considered

Additional context

This fits with the theme of #2637 of having generic array definitions for each underlying array layout