[STORY] Display error spans in Gantt chart

[AndrewHess]

Description

Note: #789 needs to be merged first

The tracing UI shows how many spans had an error

But when you click that trace to go to the Gantt chart, it's not easy to see which spans had an error.

Once #789 is merged, the frontend will have the Status field for each span in the chart. Use this field to color error spans a distinct color (maybe red).

Acceptance Criteria

If you click on a trace with some error spans, those error spans are a different color than the rest of the spans, so they are easy to identify.