Automatically include SLURM_* environment variables in metadata

[alahiff]

It might be useful if the client automatically includes all SLURM_* environment variables as metadata, or at least a subset. In particular those related to resources allocated are probably most useful, e.g.

SLURM_CPUS_PER_TASK=2
SLURM_TASKS_PER_NODE=1
SLURM_NNODES=1
SLURM_NTASKS_PER_NODE=1
SLURM_NTASKS=1
SLURM_JOB_CPUS_PER_NODE=2
SLURM_CPUS_ON_NODE=2
SLURM_JOB_NUM_NODES=1
SLURM_MEM_PER_NODE=2000
SLURM_NPROCS=1
SLURM_TRES_PER_TASK=cpu:2

Job id is probably also useful, e.g.

SLURM_JOB_ID=5687940

[kzscisoft]

@alahiff rather than do this I have added a feature to allow the user to specify environment variables they want to track within a run either using the simvue.toml (see here):

[run]
record_shell_vars = ["SLURM_*"]

or when initialising a run:

with simvue.Run() as run:
    run.init(..., record_shell_vars=["SLURM_*"])