EX-7948 utils: lamigo to track mirror progress

EX-7948 utils: lamigo to track mirror progress

pass --stats to lfs mirror/resync commands and then read
lfs's output over ssh channel.
this way we can keep ssh channel alive and interrupt
replication if it doesn't report progress.

the very first time agent is used lamigo checks whether
agent's lfs utility supports stats.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: Iee5b43cb85dae62550d74667b16e00336f1bf52f
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51744
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alexandre Ioffe <aioffe@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>