Replace vpicio and bdcats with multiple time step version

[houjun]

Related Issues / Pull Requests

Description

Replace vpicio and bdcats with multiple time step version.
Also fixed a MPI_Barrier issue that may be triggered when some client need to send the data to multiple servers while others only need to send to one server.

What changes are proposed in this pull request?

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality not to work as expected; for instance, examples in this repository must be updated too)
• This change requires a documentation update

Checklist:

• My code modifies existing public API, or introduces new public API, and I updated or wrote docstrings
• I have commented my code
• My code requires documentation updates, and I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[houjun]

Leave the commented out for now as a placeholder, may need to revisit the barrier setting if we need performance improvement.

[houjun]

@jeanbez, the "NERSC / Perlmutter" CI check doesn't seem to report back to github even after all are passed, any idea?

[jeanbez]

@jeanbez, the "NERSC / Perlmutter" CI check doesn't seem to report back to github even after all are passed, any idea?

Should be okay now @houjun any other changes for @TheAssembler1 ?