slurm_wckeys_setup.sh must add wckeys with sacctmgr

[rezib]

Currently, the script slurm_wckeys_setup.sh adds wckeys using SQL requests in SlurmDBD database. This is error prone as the DB schema is not stable and direct modification to the database is not supported by Slurm and SchedMD. The script must use supported and documented way to add wckeys, with sacctmgr command.

[mehdid]

I hear sacctmgr doesn't work well to manipulate wckeys in the database.