Implement mission control

[ppg]

Need a node who directly or indirectly listens to the button and controls the led to tell status of the car.

1. When it starts it should load the hardcoded (for now) occupancy grid.
2. When the button is pressed it should reset its position to 0,0:0.0, load the waypoints and start navigating.
3. Subsequent button press should emergency stop the car.
4. LED should blink on first button press for a second and then go.
5. LED should blink on second button press (differently) to indicate stop.
6. LED should blink another different way to indicate navigation complete.