Structs for BPC Messages

TODO: insert structs for input/output for each node in BPC

Route Planner Node

The route planner node is built off of the autoware message HADMapRoute, and is called by the same name: voltron_msgs/msg/had_map_route.hpp supplies voltron_msgs::msg::HADMapRoute, a drop-in replacement for the Autoware version that adds secondary_segments to hold the lane changes.