Related

Closes #10658
Somewhat a follow up to #10647

What

• I added a check for improper AnyValues usage (providing a value rather than kwarg) and that blew up the example since it was setup wrong
• Debugging this issue I hit
  • Numpy arrays of non-numeric types don't work for dlpack (check for BufferError)
  • Empty AnyValues are valid when used later, so I narrowed my check
  • Add an additional check for empty batches since that combined with my narrow check should prevent foot guns
  • Update our unit tests to better cover this