performance: add script to test latency with small messages

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
thorium: add basic code for doing message batching in workers

Link: https://github.com/GeneAssembly/biosal/issues/751
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>