Pipeline Graph Structural Update: Get Performant

What does this MR do?

Moves the GraphQL query for the big pipeline into startup.js for extra perf action.

Screenshots (strongly suggested)

main + upstream	main + downstream

Does this MR meet the acceptance criteria?

Conformity

• Code review guidelines
• Merge request performance guidelines
• Style guides

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)