Address remaining issues with MFEMSidreDataCollection

[joshessman-llnl]

#318 moves the SidreDataCollection class from MFEM into Axom, but the feature is not enabled by default. Before this can be enabled, the following issues need to be addressed (per @kennyweiss):

• Build the MFEM TPL with MPI when Axom is built with MPI, per Feature/white238/loosen conduit variants #319 (comment) and Feature/essman/bring in sidredc #318 (comment) - Use parallel mfem for Axom's TPL #680
• Resolve an issue with sidre::IOManager not writing the protocol used to the file when saving, preventing visualization with VisIt when running in parallel 2020-10-15: This appears to be working as expected - the provided example can be read in with VisIt when running in parallel
• Need to ensure that the convert_sidre_protocol example builds on Windows
• (possibly) Construct GridFunction and Mesh objects when an MFEMSidreDataCollection is loaded from a file such that the state of the object is identical to the object that was saved - see Sidre data collection and reloading data mfem/mfem#1776 - Add support for mesh/field reconstruction in MFEMSidreDataCollection #379 and Add support for parallel mesh reconstruction in MFEMSidreDataCollection #445

[joshessman-llnl]

We should also look into eliminating the requirement that meshes/fields be explicitly constructed as "owned" by the datastore, see #379 (comment)

[joshessman-llnl]

Once reconstruction for parallel meshes is implemented we should look at ensuring coherency between the mfem::Mesh object and the contents of the datastore as refinement can cause them to diverge.

[rhornung67]

We should also look into eliminating the requirement that meshes/fields be explicitly constructed as "owned" by the datastore, see #379 (comment)

@joshessman-llnl we support this capability already if I understand your point. Indeed, this is how Miranda uses Sidre in MARBL.

[white238]

Random info to help finish this issue off:

convert_sidre_protocol is not being built in the Github Actions windows CI because MPI is off.

https://github.com/LLNL/axom/actions/runs/4120664761/jobs/7115614836#step:8:42

[rhornung67]

Close and move third checkbox to new issue.

Note issue about relying on MFEM internals in implementation.