Add a dedicated label argument to gstlal_inspiral_postcohspiir_online to label SPIIR uploads
Labels to pipeline uploads can be applied to the initial event creation. See: https://ligo-gracedb.readthedocs.io/en/latest/api.html#ligo.gracedb.rest.GraceDb.createEvent
Currently, we have hardcoded the EARLY_WARNING label for negative latency runs. In the event of applying additional labels, this functionality can be done by using an argument within gstlal_inspiral_postcohspiir_online for labels.