Introduce Link Statistics and Latency Measurement

[gemenerik]

This PR introduces a framework for link statistics, enabling the tracking of various metrics, starting with latency measurement.

• LinkStatistics Class: A new class to manage multiple types of link statistics, facilitating the addition of more metrics in the future.
• Latency Measurement: A dedicated Latency class is introduced to send periodic ping requests to the Crazyflie. It calculates the round-trip latency and maintains the 95th percentile (p95) latency over recent measurements.

The implementation improves the lib's ability to monitor communication quality and lays the groundwork for further enhancements in link statistics.

[gemenerik]

If you want to play around with it, I suggest printing in the _ping_response method

[knmcguire]

connected to #469

[knmcguire]

Anyway to attach a caller to this for this so that we can do a callback for each Crazyflie instance? Trying to find a good example to do that in a good way... the only one I could think of is the link_quality_callback but that's perhaps not the same level

[gemenerik]

I would also like to discuss, before we merge, the ping interval, how many measurements we store, and if p95 is the best option

[gemenerik]

Anyway to attach a caller to this for this so that we can do a callback for each Crazyflie instance? Trying to find a good example to do that in a good way... the only one I could think of is the link_quality_callback but that's perhaps not the same level

Something like a Caller that you can attach a callback to for when a new latency value has arrived? I think cflib/crazyflie/console.py is a neat example of this. Or do you mean something else?

[knmcguire]

Ah yes the console is a good option indeed. It's just that printing in a different thread gives issues sometimes, and I'd like to test it out with crazyswarm2 as well.

[gemenerik]

Ah yes the console is a good option indeed. It's just that printing in a different thread gives issues sometimes, and I'd like to test it out with crazyswarm2 as well.

Yeah I think adding a Caller could be neat, we can use it to update some UI feature in the client too. I can add it.