Refactor quarantine helper

What does this MR do?

Refactor quarantine helper by moving methods closer to where they are called.

This change follows the code style suggested in the book Clean Code, by Robert. C Martin.

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