Draft: More elaborate throughput bar graphs

Goes with lhcb/LHCb!12345

• Enhances the information in the bar graph with something that can be compared between runs -- number of reference node equivalents
• Sets the range of the plot to a rounded number of reference node equivalents such that one can flip between two runs and see differences easily.
• Extends the "framework" bar with the time spent in the scheduler (e.g. in clearing the event store)
• Adds a bar for the time spent outside the event processing threads (the difference between the timing of event processing threads and the overall timing for the throughput, see LHCb MR)