Request: Separate Out Resampling Strategies Interface

[ParadaCarleton]

I'd like to use the interface for resampling strategies separately from MLJBase in ParetoSmooth.jl, but MLJBase is a pretty big dependency to add for such a small interface. Would it be a good idea to separate out an MLJResampling package similar to what's been done with LossFunctions.jl?

[ablaom]

I think it's a good idea and reasonable request.

Another possibility would be to use https://github.com/JuliaML/MLDataPattern.jl instead.