LU-12410 lnet: Implement DLC wrapper for cfs_parse_nidlist

LU-12410 lnet: Implement DLC wrapper for cfs_parse_nidlist

Implement a simple wrapper around cfs_parse_nidlist to be used by DLC
commands. The wrapper serves to sanitize the nidstr, so that is
suitable to be input to cfs_parse_nidlist. We do not want to allow an
asterisk character in this string because the resultant nidlist, when
expanded, would define too many nids for the various operations that
will utilize this functionality.

Test-Parameters: trivial
Signed-off-by: Chris Horn <hornc@cray.com>
Change-Id: I59280317af4af05eca1c8c598eadf8871e28bcf1
Reviewed-on: https://review.whamcloud.com/35304
Reviewed-by: Petros Koutoupis <pkoutoupis@cray.com>
Reviewed-by: Shaun Tancheff <stancheff@cray.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>