Benchmark Sniffnet performance

This issue wants to track the need for a benchmark to accurately measure the speed of the app, measured in packets per second (pps) that can be handled without dropping frames.

This is necessary to find out ways that can help improving the performance even further.

Today I tried testing Sniffnet with iperf on a different machine and I could observe that the current packets per second limit is higher than 100k:

Originally discussed in #373