make SupportResults struct readonly

[cwsmith]

This PR makes the CSR stored in the SupportResults struct read only.

Note, I'm not sure what should be done with the radii2 member of the struct. Should it be removed?

All tests are passing on the SCOREC checkers workstation with the following cmake config. DEVICE_ARCH is set to AMPERE86.

export NVCC_WRAPPER_DEFAULT_COMPILER=`which mpicxx`

bdir=$DEPENDENCY_DIR/${DEVICE_ARCH}/pcms
set -x
cmake --debug-find-pkg=meshfields -S pcms -B $bdir \
  -DCMAKE_INSTALL_PREFIX=$bdir/install \
  -DCMAKE_CXX_COMPILER=`which mpicxx` \
  -DCMAKE_C_COMPILER=`which mpicc` \
  -DCMAKE_BUILD_TYPE=Release \
  -DOmega_h_DIR=$DEPENDENCY_DIR/${DEVICE_ARCH}/omega_h/install/lib64/cmake/Omega_h/ \
  -Dredev_DIR=$DEPENDENCY_DIR/${DEVICE_ARCH}/redev/install/lib64/cmake/redev/ \
  -DPCMS_TEST_DATA_DIR=pcms_testcases \
  -DMPIEXEC_EXECUTABLE=`which mpirun` \
  -DKokkos_DIR=$DEPENDENCY_DIR/${DEVICE_ARCH}/kokkos/install/lib64/cmake/Kokkos/ \
  -DKokkosKernels_DIR=$DEPENDENCY_DIR/${DEVICE_ARCH}/kokkos-kernels/install/lib64/cmake/KokkosKernels/ \
  -DPCMS_ENABLE_MESHFIELDS=on \
  -Dmeshfields_DIR=$DEPENDENCY_DIR/${DEVICE_ARCH}/meshfields_caboff/install/lib64/cmake/meshfields \
  -DBUILD_TESTING=ON

cmake --build $bdir --target install -j20
set +x

[jacobmerson]

Looks good to me. @abhiyanpaudel If you don't have any issues I will merge.

[abhiyanpaudel]

Looks good to me. @abhiyanpaudel If you don't have any issues I will merge.

sure, you can merge