inspiral_range should use cosmologically-corrected ranges

Created by: jrollins

It looks like the inspiral_range function will now be using the inspiral_range package to calculate ranges, which is good. However, it looks like it's still just calculating the "sensemon" range, which is inaccurate at cosmological distances. It would be good if by default it used the cosmologically-corrected range function, or at least make the other functions available to users so they're not limited to just the sensemon range.

Another possibility would be to deprecate the gwpy.astro.inspiral_range package and to just point users to the external inspiral_range package, which may in some way be cleaner and less confusing. At the very least this package should be referenced for people looking for a more accurate range estimate.