Implement method for deleting remaining jobs

What does this MR do?

Adds a method that deletes remaining running background jobs. This is useful when there's a problem with the background jobs that's discovered after scheduling them.

Related !51821 (merged)
Related !51822 (merged)

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• N/A Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• N/A Separation of EE specific content