Pipeline Graph Structural Update: Adjust Links Rendering

What does this MR do?

Removes link display from pipeline graph (by stage). Moves the data collection up a level, so we can still find out some general facts about pipeline sizes.

Note, this does not remove the functionality entirely as it will be back with #298930 (closed).

Screenshots (strongly suggested)

Notice lack of links on hover.

Does this MR meet the acceptance criteria?

Conformity

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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)