[Feature]: Implement publisher for new Message type from planning

[THDThieleT]

Feature Description

Planning got two new messages, Trajectory and NavigationPoint.
The Trajectory message needs to be published.
The simple Publisher should publish dummy data.

Later on a new Issue is needed in which the data that is published needs to be adjusted to the new structur that was defined in #487

Definition of Done

Planning has a publisher which published a Trajectory.msg onto the "planning_trajectory" topic.

Testability

1. Start the leaderboard
2. check in rqt if topic "planning_trajectory" is published
3. Leaderboard works like usal
4. With attaching a shell, topic can also be checked using rostopic echo /planning_trajectory

Dependencies

No response