check process binding

[smoors]

this runs a short test in a prerun cmd to get the process binding, which is checked with the check_process_binding.py script.

fixes #307

the results are written into the job error file.

the test currently doesn't fail on binding error, as we don't yet have a bullet-proof solution for setting the binding in all cases (see also the discussion in #305).

so for now, both the errors and warnings are printed as warnings on screen, adding sanity checks can be added in a follow-up PR.

example:

PROCESS BINDING ERROR: wrong number of processes: expected 3, found 5
PROCESS BINDING ERROR: wrong number of cpus per process: expected 4, found Counter({2: 5})
PROCESS BINDING WARNING: processes spanning multiple packages: Counter({2: 1})
PROCESS BINDING WARNING: processes spanning multiple numanodes: Counter({2: 3})
PROCESS BINDING WARNING: processes with cores shared by processing units, indicating hyperthreading: Counter({2: 2}),

note: i was able to get the correct launcher run command by updating the job resources in the assign_tasks_per_compute_unit function. this also allowed simplifying the openfoam test and make it more robust.