Inconsistent beam handling

[hughbg]

The original healvis defines its AnalyticBeam to be a baseline beam not an antenna beam (this is made clear in the healvis wrapper for hera_sim). This is why it is not squared. This is inconsistent with the pyuvsim AnalyticBeam. Therefore, check which beam is being used in the healvis code.

The use of per-antenna beams will make setup_observatory_from_uvdata() fail or setup incorrectly. It must be changed.