resource utilization tracking - include signature events from the processing

[magland]

From @luiztauffer

"thinking on ways we could push this visualization to be even more informative, we could have signature event logs from the Processor included there, optionally. These signature logs would be picked up by a parser (I’m not sure if in the parent process?), they would have a specific signature, e.g. [DENDRO-EVENT-LOGGER] - [timestamp] - [logged event message], which would allow us to parse it from regular processor logging.
We would be able to create event markers in the resources utilization graphics: source file loaded, preprocessing finished, spike sorting started, etc..."

That's a good idea. Should be easy to implement once we pin down the format for the signature events.