Update pipeline detail view to accommodate post-merge pipelines

What does this MR do?

Updates the pipeline detail view to handle the three cases mentioned in the Pipeline detail view widget section here: https://gitlab.com/gitlab-org/gitlab-ee/issues/7380#pipeline-detail-view-widget. The relevant UI mockups from this issue have been copied below for convenience:

Requirements	Mockups
Normal branch pipeline Copy from changed to for
Detached merge request pipeline Ref now shows merge request ID/Link before the source branch merge request tag is removed Detached tag is added Copy from changed to for
Merged result merge request pipeline Ref now shows merge request ID/Link before source branch and adds target branch merge request tag is removed Copy from changed to for

This MR assumes the pipeline API will be updated as described in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25679.

What are the relevant issue numbers?

Related gitlab-ee#7380 #58454 (moved)

https://gitlab.com/gitlab-org/gitlab-ee/issues/7380

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25679

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [-] Documentation created/updated via this MR
• [-] Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• [-] Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• [-] Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer