Currently rendering is overly complex due to the async loading of individual stage data for runs. This can be refactored to be simpler and use more direct templating, which makes JENKINS-33185 easier to execute.

1. Don't cache/request individual stages, instead use the runs table (already stored) and NEVER issues requests for individual stages.
2. Refactor tests dependent on the stage/run separation
3. Pull out the stuff that fetches stage descriptions (probably for popups) and tie it to initial templating with run data.
4. Add full stage data to JS test cases