Probe all USB ports on Darwin

[tryuan99]

This PR fixes SerialMoteProbe to probe all /dev/tty.usb* ports instead of only /dev/tty.usbserial-* ports.
When I connect an nRF52840-DK board to my M1 mac, the device shows up as /dev/tty.usbmodem0006837436331, which I can confirm belongs to the nRF board.

Example of a log after running openv-server:

23:38:05 WARNING Probing motes: ['/dev/tty.usbserial-100', '/dev/tty.usbserial-101', '/dev/tty.usbmodem0006837436331'] at baudrates [115200]
23:38:09 SUCCESS Discovered serial-port(s): ['/dev/tty.usbserial-101', '/dev/tty.usbmodem0006837436331']
23:38:09 INFO extracting firmware definitions.
23:38:09 VERBOSE extracting firmware component names
23:38:09 VERBOSE extracting firmware log descriptions.
23:38:09 VERBOSE extracting 6top return codes.
23:38:09 VERBOSE extracting 6top states.
23:38:09 SUCCESS connected to broker (argus.paris.inria.fr) for mote on port: /dev/tty.usbserial-101
23:38:10 INFO starting RPC server
23:38:10 SUCCESS connected to broker (argus.paris.inria.fr) for mote on port: /dev/tty.usbmodem0006837436331