LU-4239 tests: test FID related APIs

LU-4239 tests: test FID related APIs

This adds a few stress tests to the user lustre API, related to FIDs.

Change-Id: I34144a8f4c446e55c6630d31cae6a133d61eb304
Signed-off-by: Frank Zago <fzago@cray.com>
Test-Parameters: alwaysuploadlogs envdefinitions=ONLY=154g testlist=sanity
Reviewed-on: http://review.whamcloud.com/12545
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>