Refactored the UART bridge. Notable changes include
Header now is two bytes, a message ID, and a the body length.
Pico firmware now registers UART callback as a per-object basis instead of per-module. For example, a binary_output struct can be setup and registered along with its callback. When a message arrives with the corresponding ID, the callback is called and the binary_output struct is passed to it. This leads to more code in the setup script but much better flexibility.
Refactored the UART bridge. Notable changes include