Exceptions from constructing the protocol object should have enumerated errors instead of raw integers

[jbrover]

try/catch statements when constructing the protocol object currently check values -1, -2 etc.

These should be enumerated in librover.

https://github.com/RoverRobotics/roverrobotics_ros2/blob/fixes/roverrobotics_driver/src/roverrobotics_ros2_driver.cpp