Update nav2_gps_waypoint_follower_demo

[pepisg]

In this PR I picked up the work started in #16, updating the branch to match the changes made here.

As #16, this PR aims to demostrate the usage of the nav2_gps_waypoint_follower introduced here and continued here.

[Ryujiyasu]

@pepisg @SteveMacenski
Hi ! this thread still alive?

I want to use Navigation2 outside. so I checked this thread and checked to work in My Environment(1GPS and 1IMU + Lidar(not use)).

Results is below video. it is almost work... please tell me what shold i do next??

https://www.youtube.com/watch?v=kbyiNRClYec

thank you!!

[Ryujiyasu]

ros2 action send_goal "follow_gps_waypoints" nav2_msgs/action/FollowGPSWaypoints '{gps_poses: [{position: {latitude: 33.8301, longitude: -84.42, altitude: 0.0}, orientation: {x: 0.0, y: 0.0, z: 0.0, w: 1.0}},
{position: {latitude: 33.8301, longitude: -84.4201, altitude: 0.0}, orientation: {x: 0.0, y: 0.0, z: 0.0, w: 1.0}},
{position: {latitude: 33.83, longitude: -84.4201, altitude: 0.0}, orientation: {x: 0.0, y: 0.0, z: 0.0, w: 1.0}},
{position: {latitude: 33.83, longitude: -84.42, altitude: 0.0}, orientation: {x: 0.0, y: 0.0, z: 0.0, w: 1.0}}]}'

[SteveMacenski]

I think I'm waiting on @pepisg for the world files to be removed or made clear that they need to be here so I can review the rest of this. Also the complimentary PR in navigation.ros.org for the documentation / tutorial around this source code (I think mostly what we're waiting on so these can be merged at the same time).

Great to know this works through on your robot, that's a great sign!