Update DAST report fixture, Fix deduplication logic

What does this MR do?

This reverts !18670 (merged) and fixes the QA specs.

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

Relevant to #13034 (closed) and #11930 (closed)