LU-15234 lnet: add mechanism for dumping lnd peer debug info

LU-15234 lnet: add mechanism for dumping lnd peer debug info

Add ability to dump lnd peer debug info:
	lnetctl debug peer --nid=<nid>

The debug info is dumped to the log as D_CONSOLE by the respective
lnd and can be retrieved with "lctl dk" or seen in syslog.
This mechanism has been added for socklnd and o2iblnd peers.

Lustre-change: https://review.whamcloud.com/48566
Lustre-commit: 950e59ced18d49e9fdd31c1e9de43b89a0bc1c1d

Test-Parameters: trivial testlist=sanity-lnet
Signed-off-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Change-Id: Ia9c4d59143206bcb7ec43806594cf0cfaed5f0a9
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/49038
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>