Add retrieval activity logs

[juliangruber]

To help Station operators understand what's going on

[juliangruber]

https://github.com/filecoin-station/spark/releases/tag/v1.6.0-rc.1

[juliangruber]

filecoin-station/core#266

[bajtos]

LGTM; with a few suggestions that can be applied in a follow-up PR if you like.

[bajtos]

On the second though, I am not sure if this PR is a good idea. I think we will overload the user with too many detailed messages that will make it difficult to notice the important ones.

If we want to show progress, then aggregated information printed once every X seconds is a better approach, IMO. We are already discussing new activity logs here: filecoin-station/desktop#1123

To allow our users to troubleshoot Station behaviour in details, the current "Save Module Logs as" approach is IMO better. We can review what messages is SPARK printing to this log file via console.log and console.error APIs and add more logging where needed.

Thoughts?

/cc @patrickwoodhead

[juliangruber]

I agree that showing summaries is more effective from a data perspective than reporting any individual retrieval. Let's revisit in our call