add message tags for counting in parallel

Link: https://github.com/GeneAssembly/biosal/issues/266
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
send spawners for parallel count

Link: https://github.com/GeneAssembly/biosal/issues/266
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>