Display running average of metrics during rollout generation + scoring

[mikasenghaas]

Would be cool to show a running avg. of metrics during generation+scoring, most basic ones i can think of are reward and seq_len in the tqdm bar description, that are updated as rollouts complete

[anakin87]

@mikasenghaas I started experimenting with this idea. By seq_len, do you mean the completion length?

[mikasenghaas]

probably completion len yea

[anakin87]

I'll open a PR soon (in the next few days)

[anakin87]

@mikasenghaas is this still relevant? I opened #443 but will require more work after the eval refactoring. LMK and I'll adapt my PR.