Slurm accounting federation

[rvencu]

Looking at https://github.com/aws-samples/pcluster-manager/blob/main/resources/scripts/slurm-accounting.sh I can see you are setting slurmdbd service on headnode

Federation will not work well with a single database and multiple slurmdbd processes, as per slurm support.

Instead, we need a single slurmdbd process on a remote machine (maybe set that up inside database cf template) and configure slurmctld from each headnode to connect to it.