Muon Front End: Separator spark events investigation

As a developer supporting the MUONFE separator PSU, I would like to know how the current and voltage signals behave around spark events so that I understand how to detect sparks.

**Notes:**
- A plot that shows both the current and voltage while it’s sparking with the same time axis and different voltage and current Y axes may be useful. To create such a chart using the Altair charting library, see https://altair-viz.github.io/gallery/layered_plot_with_dual_axis.html.
- A chart which also overlays the spark events picked out the naive algorithm developed in #3875 on top of the chart above may also be useful
- Voltage and current data with spark events (which were created by ramping up the separator PSU) can be found on the share.