Add launch module to ardupilot_sitl package
- Move body of launch scripts into package for reuse.
- Add utilities module.
Update launch scripts
- Provide type hints.
- Add arguments to sitl.launch.py.
- Fix formatting bug in sitl.launch.py home argument.
Update micro_ros_agent launch script
- Modify import for lauch_ros.actions.Node.
- Change argument order in node initialiser.
- Add args for UDP transport and set as default.
Update ROS 2 DDS default params
- Add default params for both serial and UDP transports.
- Add DDS_ENABLE.
Rename ROS 2 sitl_dds launch script
- Rename sitl_dds launch script with serial suffix.
- Add launch script for UDP transport.
Update ROS 2 launch test fixtures
- Make common test fixtures more granular.
- Add fixtures and tests for UDP transport.
- Update ROS 2 package.xml dependencies
- Use yield rather than return in test fixtures.
- Use ardupilot_sitl launch module directly.
- Correct return type descriptions.
- Fix flake8 failure.
Update ROS 2 README
- Update launch instructions.
Signed-off-by: Rhys Mainwaring <rhys.mainwaring@me.com>