Tracing / grouping of logs

[tj]

I'm hesitant to call it tracing since this would have to utilize the "working set" (logs in-memory on the client), but as long as they're visible we could have an option to display them as a trace. This couldddd be fine for the majority of cases, where requests span maybe a few seconds at most for example.

There are a few options, we could special-case a field such as trace_id, and then display the trace based on that, and/or have clicking a field show a "group by" option, which would group all visible logs by that field to help organize. Need to think about it some more :D