Add a link to the 'danger-review' job

What does this MR do?

This adds a simple message to let the users know where to find the the danger-review that generated the message so that they can retry it if needed.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines
• Style guides
• Separation of EE specific content

Closes #210311 (closed).