Wrap vehicle topics around a namespace

To make SWIL and HWIL testing compatable, topics produced from can_to_ros need to be prefixed with a namespace, preferably `/vehicle/` or `/VIN` if possible.

For example, 
```
/accel
/cmd_accel
/cmd_vel
/commands
```

is recommended to be like

```
/vehicle/accel
/vehicle/cmd_accel
/vehicle/cmd_vel
/vehicle/commands
```