LU-15461 test: add pool quota check

LU-15461 test: add pool quota check

The test_79 in sanity-quota needs quota pool support.
The removal of the "stop file" is also improved not to
trigger the test error if it has been deleted.

Lustre-change: https://review.whamcloud.com/52737
Lustre-commit: TBD (from a4b3cd91ae157a63644350769ebb248f21dd6eac)

Test-Parameters: trivial testlist=sanity-quota
Signed-off-by: Hongchao Zhang <hongchao@whamcloud.com>
Change-Id: I4acd36e61faf4259c2821293ffb7913d4cca76bd
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/52659
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>