Implement Arm over-extension prevention system

[blu28]

The Arm is not allowed to extend further outside of the robot FRAME PERIMETER than 4'6". However, when fully extended the arm goes beyond that limit. In order to pass inspection, we have to be able to demonstrate to the inspector that the robot's arm will never extend beyond the limit, either because it is prevented from doing so in hardware or software. The plan is to detect when the arm is below the angle at which it can extend too far, and force it to retract if it is extended, or prevent it from extending if it is retracted. There is a proposal to use a strip of LED lights to signal to the operator that the extension interlock is engaged.

See https://nashua151.slack.com/archives/C04HXK97X9R/p1677515614085529 for the diagram explanation.