LU-18462 nodemap: sanity checks for positional parameters

LU-18462 nodemap: sanity checks for positional parameters

A number of nodemap commands just take positional parameters instead
of options:
- nodemap_activate
- nodemap_add
- nodemap_del
- nodemap_test_nid
In this case, we need to check manually that we got the correct number
of arguments, and return a proper error message otherwise.

These commands are also modified to grok named options, in addition to
positional parameters that we will have to keep for some time for
backward compatibility reasons.

Test-Parameters: trivial testlist=sanity-sec
Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: Ie515e8e03f30581c7fb84efa3f881769fc02a397
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/57087
Reviewed-by: Marc Vef <mvef@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>