Support for Logging Data of USB Serial Interface

[fish-in-the-sea]

Add support for sending the log data over the usb serial interface of the fed3 unit

[matiasandina]

@fish-in-the-sea we developed fedwatcher for that purpose https://github.com/matiasandina/FEDWatcher. It's not via USB, but using softwareserial and the BNC/jack. It might still work for your purposes. Happy to help.