Send regular update messages from the locomotion Arduino to the Jetson

In HeadLocomotion.ino, messages are never actually sent to the Jetson despite the functionality existing - we need to add code for sending messages as part of the same response for actuating motors to keep the Jetson updated on the microcontroller's status.

Start with HeadLocomotion.ino and trace the existing motor-actuation response and the code that formats or sends status messages. Confirm how the Jetson receives locomotion responses, then add regular status data to that same response and verify that messages are emitted while motors are actuated.

Written by the indexing model from the issue text.