LU-13903 utils: separate out server code for lctl

LU-13903 utils: separate out server code for lctl

The utility lctl is used by both client and server management but
the code is not cleanly separated for each case. This breaks
building lctl for the native Linux Lustre client since it only
contains client related work. Fix up lctl to be slimed down for
client only targets.

Lustre-change: https://review.whamcloud.com/42141
Lustre-commit: 0b7ddf32e336b06d459880faf9831db43ffae9cf

Change-Id: I0c8c037087de1155e478a2580fc952629c341447
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/49779
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>