LU-14194 cksum: add lprocfs checksum support in MDC/MDT

LU-14194 cksum: add lprocfs checksum support in MDC/MDT

Add missed support for checksum parameters in MDC and MDT
Handle T10-PI parameters in MDT similar to OFD, move all
functionality to target code and unify its usage in both
targets

Signed-off-by: Mikhail Pershin <mpershin@whamcloud.com>
Change-Id: I7d397067304e028bf597d5c3ab16250731ccba9d
Reviewed-on: https://review.whamcloud.com/40971
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Li Xi <lixi@ddn.com>