UVBeam runtime / memory usage #548
Description
We've always known that UVBeam increases runtime and memory usage, but we should get a better handle on how much. Changes to runtime also seemed to have occurred in 1.4.1 but possibly in a way that hurt the runtime of Analytic Beams. See the table below, where for complete, the "dev" version in the bottom rows refers to pyuvdata 3.1.4.dev85+g7283786a, pyuvsim 1.4.1.dev62+gfc43d8a, and pyradiosky 1.0.2.dev46+gaa1cd83.
