Implement / test vehicle update loop

[tpbarron]

• [Done] Populate sensor data to get current position
• [Done] Get nearby vehicles
• Add listeners in order of ascending distance if not already a listener
• [Done] Broadcast sensor data to listeners
• Compute WARN param for data struct (this can be another task, what WARN means needs to be decided)
• Compute own vehicle data (do major computation when receive incoming data)
• [Done] Set update timer

[tpbarron]

Partial completion. Closing because of structure change. All of these will be implemented eventually.