LU-15595 tests: Add various router tests

LU-15595 tests: Add various router tests

Add test cases to exercise LNet routing.

Lustre-change: https://review.whamcloud.com/46622
Lustre-commit: 8ee85e15412d32fbe60f70c474c0a28ff15b8351

Test-Parameters: trivial testlist=sanity-lnet
Signed-off-by: Chris Horn <chris.horn@hpe.com>
Change-Id: I4a077937b3e3b8b07707afeb0c5c23ec1c9074f4
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/51661
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>