EX-8362 scripts: improve ll_compression_scan functionality

EX-8362 scripts: improve ll_compression_scan functionality

Improve ll_compression_scan script functionality without
changing the compression estimates.
- add a version string to the output to allow tracking
- handle pathnames with spaces in them
- handle the lz4fast compression type
- allow running on MacOS for testing

Test-Parameters: trivial testlist=sanity-compr env=ONLY=1007
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I0b8442a2590fdb9c718b1404cba1d73c26cff03c
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/53678
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Patrick Farrell <pfarrell@whamcloud.com>