add a wrapper around memcpy

Link: https://github.com/GeneAssembly/biosal/issues/484
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
rename bsal_packer_work to bsal_packer_process

Link: https://github.com/GeneAssembly/biosal/issues/645
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
rename BSAL_PACKER_OPERATION_DRY_RUN, to BSAL_PACKER_OPERATION_PACK_SIZE

Link: https://github.com/GeneAssembly/biosal/issues/647
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>