Migrate shared memory capability to Umpire

[kennyweiss]

We're currently using MPI3 shared memory in some quest use-cases.
We should switch this over to Umpire's shared memory capability.

We're currently using the AXOM_ENABLE_MPI3 config variable to control this

axom/src/cmake/AxomOptions.cmake

Line 33 in acdfc10

cmake_dependent_option(AXOM_ENABLE_MPI3 "Enables use of MPI-3 features" OFF "ENABLE_MPI" OFF)

To use Umpire's shared memory, we'll need to configure Umpire with UMPIRE_ENABLE_IPC_SHARED_MEMORY
See:

• https://github.com/LLNL/Umpire/blob/91ffd6fc85c63df4babd11b2253b863606ed651b/CMakeLists.txt#L91-L95
• https://github.com/LLNL/Umpire/blob/develop/examples/cookbook/recipe_shared_memory.cpp

[rhornung67]

CI test(s) should be added for this to address #244

[rhornung67]

Wait to see what Kristi comes up with in MARBL and leverage that work.

[davidbeckingsale]

We are working on adding MPI3 support for shared memory (in addition to POSIX) to Umpire.