Implement synops metric

[Jegp]

Measuring the number of synaptic operations during the forward pass of an SNN would be a useful metric.

The code is probably straight-forward to implement with hooks similar to https://github.com/norse/norse/blob/main/norse/torch/module/sequential.py#L54

[Jegp]

I'm not sure there's a strong need for this, so I'll close this until someone shouts loud enough :)

[cpehle]

I actually have been asked about this a bunch of times. Would be still good to have it especially for a publication.

[Jegp]

Fully agree. I guess the question is how to proceed. Just implementing "raw" synops metrics might be a little boring. And it's unclear to if that's helpful, mostly because I'm not sure "synops" is a commonly agreed-upon metric. Do you have an opinion here?
We could also lean on the work of others. I've been in touch with a PI from Stanford who recently developed some kind of toolbox/metric for this. Maybe that could be one approach?