Use nullsnr to validate events with 3+ ifos
Linqing has a paper on using nullsnr to validate events with 3+ ifos. It's low priority for now, but as Virgo and Kagra become cleaner and more sensitive it may be useful.
Note there was a change in spiir-production-Oct27-dev (moved to tdavies__remove_nullsnr_sqrt) to remove the sqrt from nullsnr after postcoh. We might need to verify that the sqrt isn't being done twice.
Edited by Timothy Davies