Change loading, remove async on new graph

What does this MR do?

This MR loads the code for the new graph synchronously, since the flag has defaulted on. It also updates the order of the loading so that the header loads first, since it shows no matter what, and the DAG and Test Reports load later.

Screenshots (strongly suggested)

No visual change.

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)