Antenna gain translation

[marcomuzio]

This PR adds better handling of the translation of antenna gain measurements taken in one medium into another (probably something icy??).

If an antenna gain file does not have an index of refraction, no scaling of the gain argument occurs.

This PR also removes dependence on a hardcoded freq_step_max which sets the frequency resolution. Resolution is now determined dynamically (and so a lot of variables have been updated from arrays to vectors).

This change resulted in a change to the Veff tests, since the normalization of the effective height changed (due to the index in its calculation changed from n_local to n_eff) and because the frequency resolution of the antenna models changed.

Testing summary (as of commit 313ad80)
A3 veff test: passed ✅
birefringence veff test: passed ✅
pa veff test: passed ✅
pulser veff test: passed ✅

[AlanSalcedo]

Looks good, pending determining what n to use in the normalization of effective height.

[clark2668]

Very minor comments

[clark2668]

Can we get some plots of the effective height at a couple different zenith angles comparing the measured to the shifted, just to sanity check that all looks as expected?

[clark2668]

Some relatively minor comments.

[clark2668]

For example, a plot of the heff for this event that gets tipped over into passing might be a good one.

[marcomuzio]

Let me see if I can manage a plot at all first. This isn't easy to get out of AraSim.

[marcomuzio]

Can we get some plots of the effective height at a couple different zenith angles comparing the measured to the shifted, just to sanity check that all looks as expected?

Okay that was painful to get lol. Here's a plot for some random channel.

[clark2668]

That plot is helpful to see. So it does shift down as expected. And goes up. So this is roughly what we would have anticipated. Okay, thanks.

[marcomuzio]

Okay @clark2668 I'm rerunning the veff tests, but I think I've responded to all your comments.

[clark2668]

Okie dokes! Thanks for suffering my review!

[marcomuzio]

Okay all tests have passed. Merging now.