Add PBS (SLURM) related info such as cpu_requested, peak consumption metrics

original smon has

```python
#figure out max PPN
max_ppn = os.sysconf('SC_NPROCESSORS_CONF') #default to all available cores
if "PBS_NUM_PPN" in os.environ:
max_ppn = int(os.environ["PBS_NUM_PPN"])
#from https://slurm.schedmd.com/srun.html
if "SLURM_CPUS_ON_NODE" in os.environ: #incase SLURM_NTASKS is not set?
max_ppn = int(os.environ["SLURM_CPUS_ON_NODE"])
if "SLURM_NTASKS" in os.environ:
max_ppn = int(os.environ["SLURM_NTASKS"])
...
"cpu_total": os.sysconf('SC_NPROCESSORS_CONF'),
"cpu_requested": max_ppn,
```

and it might be worth adding to `duct`