Resolve "Followup to New design for cancel/stop pipeline confirmation"

What does this MR do?

• Remove duplicate component and just use model.vue.
• $emit an event and don't use callbacks.

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Update code to follow style guidelines

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Review
  • Has been reviewed by Frontend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• End-to-end tests pass (package-qa manual pipeline job)

What are the relevant issue numbers?

Closes #42886 (closed)