Implement a pre-planned trajectory planner

[evan-palmer]

Checklist

• [x] I have performed a thorough review of my code
• [x] I have sufficiently commented my code
• [x] The implementation follows the project style conventions
• [x] All project unit tests are passing
• [x] If relevant, documentation has been provided or updated to discuss the changes made
• [x] System integration tests were performed successfully

Changes Made

This PR introduces the angler_planning package--a collection of ROS 2 nodes used to perform trajectory and motion planning with the Angler system. The base planner implemented in this PR is a pre-planned mission planner which provides a set of pre-defined waypoints for the UVMS to track.

Associated Issues

• Closes #3

Testing

Integration testing has been performed with the implementation. Unit tests still need to be implemented.

[evan-palmer]

This is generally fine as it stands now; however, in the future it will be important to think about whether serving all waypoints at once is the best approach to this. It may be valuable to instead return only points "in-front" of the robot.