Only run one test with 3 waveform models
The purpose of this MR is to simplify the testing suite to run the majority of tests with only one waveform model: IMRPhenomXPHM
. We still run the GW150915:analytic_localization
test with 3 waveform models: IMRPhenomXHM/IMRPhenomXPHM/IMRPhenomTPHM
.