LU-14889 lproc: Add server checksum_type

LU-14889 lproc: Add server checksum_type

This patch adds 'checksum_type' lproc entries under server:
1. obdfilter.$FSNAME-OST${count}.checksum_type
2. mdt.$FSNAME-MDT${count}.checksum_type

Test-case: sanity/77o added

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I12a26f5c8c8f2f93d57f377626b1753fc13ffbb3
Reviewed-on: https://review.whamcloud.com/44755
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>