Pipeline Graph Structural Update: Create Legacy Linked Pipelines Column

What does this MR do?

This adds legacy linked pipelines components as a basis for the new linked pipelines code. I've made it a separate MR so that we can have fewer lines of code, unlike !48330 (merged).

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.

Related to #276949 (closed)