LU-13569 lnet: Add health ping stats

LU-13569 lnet: Add health ping stats

Add the NI and peer NI ping count and next ping timestamp to
detailed output of lnetctl peer and net output.

Lustre-change: https://review.whamcloud.com/40314
Lustre-commit: 4c7e4aa57629660386ae2849151a0639b6177200

Test-Parameters: trivial
HPE-bug-id: LUS-9109
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: I208cb3ea0b08a2984572cf0ec9874dbd09f6168e
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/54405
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>