Add ADC overflow plugin
This merge request adds a plugin to monitor ADC overflows from various subsystems (ASC, LSC, OMC).
It shows overflows in any of the bits in the ADC during those times. It also contains two overview plots (full, zoomed) that essentially does a union of all those segments for a particular ADC and maps out if any of those bits overflowed during that time, so that you only have to look at a specific subsystem if something interesting happened in the overview plots. These are linked up side-by-side (full/zoomed) in the webpages.
I have some example plots from one of the times around the fast lock losses on 10/04: