[Vue] remove use of piwik-enrichedheadline in event listener

[diosmosis]

Description:

As title.

Review

• [ ] Functional review done
• [ ] Potential edge cases thought about (behavior of the code with strange input, with strange internal state or possible interactions with other Matomo subsystems)
• [ ] Usability review done (is anything maybe unclear or think about anything that would cause people to reach out to support)
• [ ] Security review done
• [ ] Wording review done
• [ ] Code review done
• [ ] Tests were added if useful/possible
• [ ] Reviewed for breaking changes
• [ ] Developer changelog updated if needed
• [ ] Documentation added if needed
• [ ] Existing documentation updated if needed

[sgiehl]

@diosmosis I'll close this PR and open a new one for 4.x-dev. The method the uses the angular stuff is actually not needed anymore, as the event being used here doesn't exist anymore.