Fix draft image comments showing in MR overview

What does this MR do?

This MR addresses #327737 (closed) which was introduced by !51718 (merged).

• Previously if you added a draft note on an image diff, it would show up in the MR overview.
• Now this isn't the case anymore.

A regression feature spec is added that fails in master

Screenshots (strongly suggested)

Before	After

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have not included a changelog entry because it is fixed in the same milestone.
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.

Related to #327737 (closed)