tag nodes with CPU (microarchitecture) based on archspec

[boegel]

list_nodes shows that workernodes are tagged with features like arch=x86_64, which is very useful when submitting jobs to specific types of nodes via sbatch --constraint.

I think it would be useful to make that a bit more fine-grained, by adding an additional feature like uarch=haswell (or perhaps something like cpu_family=haswell).

archspec would be perfect for this, since it's trivial to install (pip install archspec) and run to identify the CPU microarchitecture of nodes (archspec cpu, which produces a short human-readable string like haswell, zen2, gravition2`, etc.).

I'm happy to try and help out with this, given some pointers...