KernelImportsToArguments transformation only works with PSyKAl kernels (CodedKern)

[arporter]

It would be very useful to extend the transformation so that it works for generic routines rather than only PSyKAl kernels. Currently it gives:

psyclone.psyir.transformations.transformation_error.TransformationError: Transformation Error: The KernelImportsToArguments transformation can only be applied to CodedKern nodes but found 'NemoInvokeSchedule' instead.