LU-16627 tests: add auster long options

LU-16627 tests: add auster long options

Add long options to auster.

Update the file header to have the
SPDX license and use the standard
format.

Address a couple of small shellcheck
warnings.

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I3f1089ce6e054cd40f0afb229f9a0f0935e96d2e
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/50237
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Charlie Olmstead <charlie@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>