Docstring for bilby_to_lalsimulation_spins() should specify units

The spin conversion function bilby.gw.conversion.bilby_to_lalsimulation_spins() takes mass_1 and mass_2 as arguments, and it expects them to be in SI units. However, it has no docstring, so one might assume that they should be in solar masses. This function in turn calls bilby.gw.conversion.transform_precessing_spins(), which does have a clear docstring that specifies the units.

Looking at calls to bilby_to_lalsimulation_spins(), the waveform generators in gw.source make this conversion, but bilby.gw.conversion.generate_all_bbh_parameters() does not appear to do so. I am not sure the implications of this.