message: Bugfix: Conditionally include spio in MFEMSidreCollection
  Fixes compilation error for configurations with `sidre and `mfem`
  but not `mpi`.
diff: #include "axom/fmt.hpp"
  #include "MFEMSidreDataCollection.hpp"
  + #ifdef AXOM_USE_MPI
  #include "axom/sidre/spio/IOManager.hpp"
  + #endif
  #include "axom/core/utilities/StringUtilities.hpp"
  #include "axom/core/utilities/Utilities.hpp"
  