Access the Mac address of the device.

[matteoerrera]

Is your feature request related to a problem? Please describe.

I need to uniquely identify an ESP32 on my database and I thought the best solution might be to save the Mac Address.
However, I cannot find any reference on this repository on how to access the Mac address of a connected device.

Describe the solution you'd like

It would be convenient to have a method on the ESPDevice class to access the Mac Address of the device

Describe alternatives you've considered

I have no other ideas on how to achieve the goal stated in the introduction.
Of course any suggestions are greatly appreciated.