LU-18594 tests: add vmstat and recovery status info

LU-18594 tests: add vmstat and recovery status info

Patch adds:
   -- the ability to collect vmstat and recovery status
      info. Set VMSTAT_DELAY=value starts vmstat with delay=value,
      set RECOVERY_STATUS_DELAY=value runs:
          lctl get_param *.*.recovery_status
      every "value" seconds on victim server nodes and their pairs;

   -- the precmd and postcmd return code check and stops if the
      commands failed;

   -- minor cleanup:
      a little bit verbose ha_sleep()
      the turnable tmp directory.

Test-Parameters: trivial
Signed-off-by: Elena Gryaznova <elena.gryaznova@hpe.com>
HPE-bug-id: LUS-12232
Reviewed-by: Alexander Boyko <alexander.boyko@hpe.com>
Reviewed-by: Vladimir Saveliev <vladimir.saveliev@hpe.com>
Change-Id: I4087c73f58bf58b163f164e28b267a536569268a
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/57573
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>