Incorporate distance information in overlap integral

Due to some requests from FRB searches, there has been a need to incorporate distance information into the overlap integral.

Some preliminary work has been done on this, using a galaxy catalogue: https://git.ligo.org/brandon.piotrzkowski/gw-grb-rankingstat/-/blob/master/GW170817/calculate-overlap-galaxy-catalogue-condor.py#L411-442

However, the intent is to use the distance info from CHIME to help additionally distinguish real from false coincidences. See here for a discussion of the CHIME VOEvent schema: https://chime-frb-open-data.github.io/static/CHIMEFRB_VOEvent_Service_for_External_Subscribers.pdf