Remove emittedByOrder and isEmpty due to future deprecation

What does this MR do?

This MR replaces emittedByOrder with emitted() due to future deprecation in @vue/test-utils 1.x Also this one removes again isEmpty which were originally removed by !40215 (merged) but came back to life due to faulty rebase

See &3856 (closed) for details

Screenshots

N/A

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] 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.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done