Fix xdmf hyperslab output to operate for arbitrary dimensions

Currently, the hyperslab format is used to output xdmf files for arrays that have "unusual" dimensionalities (e.g., 2, 4, 6, etc.). The original implementation was intended to be used for surface meshes (i.e., surface mesh face labels), but it was hard coded for 2D systems. This leads to a crash when trying to load a hyperslab xdmf file in ParaView when the mesh is > 2D. The xdmf output for hyperslab needs to be generalized to work for any underlying geometry dimensionality.