The field image and robot image can be loaded or just a wireframe used.
The robot can be moved and rotated with a mouse click + drag.
The robot position is settable in robot code via the Field2d class.
This shows the FPGA time and notifier timing, and has buttons to
start/pause/step the simulation.
The GUI also pauses DS new data notifications when paused. This could be
done globally instead by blocking NotifyNewData at the HAL level?
This uses Dear Imgui to provide a cross-platform integrated GUI for robot
simulation. The GUI provides fully integrated DS and joystick support so it's
not necessary to run the official DS.
