LU-10391 lnet: update Netlink commands functionality

LU-10391 lnet: update Netlink commands functionality

Update jt_import() for the lnetctl import command to support
all the new Netlink API.

Fix a sending message bug that was due to  multiple calls
to genl_ctrl_resolve_grp() and genl_ctrl_resolve(). We
were using the special netlink socket for these calls.
That special socket has its own callbacks which don't
work with the libnl functions we are calling. Fix this
by creating an internal generic netlink socket for use
with the libnl functions.

Test-Parameters: trivial testlist=sanity-lnet
Change-Id: I1d360cc0375bc56a05ca47d58d8319a0ded0ccf9
Signed-off-by: James Simmons <jsimmons@infradead.org>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53003
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Chris Horn <chris.horn@hpe.com>
Reviewed-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>