[Bug]: slurmrestd doesn't work as it only runs as a non-root non-slurm user

[NucciTheBoss]

The slurmrestd service currently doesn't work as per the documentation, it must run as a user/group that does not possess write permissions and is not either root or SlurmUser. To get slurmrestd working, we need to create a special user within the snap that will own the slurmrestd service if activated.

We have two options here:

1. Debate using the snap_daemon user. Means that we'll have to create a special user for SlurmUser.
2. Create a slurmrestd user upon installation that can run the service for us. This should be possible since Slurm is a classic snap and not a static one.