CE backport for Dismissal Reasons

What does this MR do?

This is the CE backport for https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/12067

• Why was this btn-group margin hack needed?

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content