Mavros Update to Official ROS2 Port

[mhl787156]

This PR closes #59 by updating mavros to use the official ros2 port (https://github.com/mavlink/mavros/tree/ros2/mavros)

All settings and use should remain the same.

It removes the use of ROS1 mavros through the Ros1 parameter bridge and all of the difficulties due to this.

[mhl787156]

Running into issues with set_mode service, as mirrored by this issue: mavlink/mavros#1588. All of the sys_status plugin services unfortunately hang.

@rob-clarke perhaps a workaround is to directly use CommandLong to pass a set mode request through? Maybe have the mavros container running a few of our nodes too - something which mirrors set_mode , emergency_stop (#127 ) and others

[mhl787156]

@rob-clarke Is this ready to review and merge?

[rob-clarke]

Not quite. It's a start. I think there are still some config bits that don't work properly, especially if multiple drones are involved. It also has some of the test stuff in there from #134 which I'd like to merge before this

[mhl787156]

I believe this is now ready to merge in finally :)

[rob-clarke]

Main comments are docs need more updating. Also the install_geographiclib_datasets.sh script should be installed with mavros, so shouldn't need to download separately