Count the bytes of payload for each replication record type
Count the bytes of overhead (replication records themselves)
Include these counters in the output summary at the end of the run.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Allan Jude <allanjude@freebsd.org>
Sponsored-By: Klara Systems and Catalogic
Closes#8432