LU-16723 libcfs: refactor parser to be simpler

LU-16723 libcfs: refactor parser to be simpler

The parser code has a lot of unused complexity that can be
streamlined. Refactor the parser makes the interface simpler
from a development perspective and can provide a consistent
user experience for all of the lustre utilities.

All functions which are not used outside of the parser have
been made static. Functions which don't appear to be used at
all have been removed.

The file headers have been standardized and the SDX text
added. The function names have been changed to be more standard.

Test-Parameters: testlist=sanity env=ONLY=60a,ONLY_REPEAT=10
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I3354f213de424f51aef94c840083a4cb781d7aae
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/50583
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>