Make PrintSummary actually work for Field and CoordinateSystem.

The PrintSummary for CoordinateSystem went in an infinite loop. It was supposed to call PrintSummary of its superclass (Field), but instead it called itself.

The PrintSummary for Field only worked for fields of type vtkm::Float32. To make it work for all array types, I added a PrintSummary method to DynamicArrayHandle, and Field calls that without trying to cast to a static type.