Update the minimum VTK-m to 2.1
VTK-m 2.1 contains some important features to support reading and writing vector fields of different sizes. FIDES is updated to require this newer version to take advantage of these features.
VTK-m 2.1 contains some important features to support reading and writing vector fields of different sizes. FIDES is updated to require this newer version to take advantage of these features.