feat(tier4_control_msgs): add moderate stop interface service and message

[brkay54]

Related Links

Description

#82 (comment)
With this comment, we decided to add a new interface to make the vehicle stop while moving. Therefore, we want to add the new message and service files.

Remarks

Pre-Review Checklist for the PR Author

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

• Code is properly formatted
• 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
• Code is properly formatted
• 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
• Write release notes

CI Checks

• Build and test for PR: Required to pass before the merge.
• Check spelling: NOT required to pass before the merge. It is up to the reviewer(s). See here if you want to add some words to the spell check dictionary.

[brkay54]

@isamu-takagi Could you review this PR too, please? 🙏🏼

[isamu-takagi]

LGTM

[brkay54]

@isamu-takagi Also I do not have write access to this repository. Can you merge it, please? 🙏🏼