Consider adding a variadic version of Mapping.applyForward and applyInverse that takes a separate vector for each axis. AST works this way internally, so it could be implemented without copying data, and it would allow data where each axis comes from from different column of a catalog to be transformed.

The one use case we have right now is the vector version of TransformBoundedField::evaluate. Presently it has to copy its inputs, but with this ticket it could avoid making the copy.

I'm not convinced this is worth the work, but this ticket serves as a placeholder in case we decide to do it.