[FEATURE] Merge pilot_app and debug_app into a single pilot_app that uses ROS params

[benjaminwp18]

Is your feature request related to a problem? Please describe

It's annoying that gui/pilot_app.py and gui/debug_app.py have so much shared code.

Describe the solution you'd like

Merge the functionality of pilot_app and debug_app into a single gui/pilot_app.py file that uses a parameter to determine GUI layout.

Additional context

We're already using a parameter here; do something similar:

simulation_param = self.node.declare_parameter('simulation', False)

if simulation_param.value:
    front_cam_type = CameraType.SIMULATION
    bottom_cam_type = CameraType.SIMULATION
    depth_cam_type = CameraType.SIMULATION
else:
    front_cam_type = CameraType.ETHERNET
    bottom_cam_type = CameraType.ETHERNET
    depth_cam_type = CameraType.DEPTH