chore(nebula_ros/launch): supply choices for sensor_model launch argument

[mojomex]

PR Type

• Improvement

Description

Add all supported sensor models as choices for their respective launch file's sensor_model argument. This makes ROS 2 check if the model is spelled correctly at launch time, thus improving usability.

Review Procedure

Check if Nebula still launches, and if all sensor models are mentioned.

Pre-Review Checklist for the PR Author

PR Author should check the checkboxes below when creating the PR.

• Assign PR to reviewer

Checklist for the PR Reviewer

Reviewers should check the checkboxes below before approval.

• Commits are properly organized and messages are according to the guideline
• (Optional) Unit tests have been written for new behavior
• PR title describes the changes

Post-Review Checklist for the PR Author

PR Author should check the checkboxes below before merging.

• All open points are addressed and tracked via issues or tickets

CI Checks

• Build and test for PR: Required to pass before the merge.

[knzo25]

LGTM