Port of single scattering radar of ARTS2

[riclarsson]

This is a port of single scattering radar from ARTS2 to ARTS3.

It is entirely AI-guided. So I cannot merge this without review from @erikssonpatrick and @m-brath .

There are two parts to this PR:

1. The port of the scattering data
2. The addition of a RayleighScattering ScatteringSpecies. I designed the latter to work like species tag for absorption models so that both the water droplet model that the AI ported from ARTS2 and the air-model that was used in the ARTS2/3 solar scattering calculations can be used.

Anyways, this needs a proper review because I am not sure how to test the radar other than trying to recreate the test in ARTS2, and I am not sure that that has been done correctly.

[riclarsson]

@m-brath I need your help reviewing the scattering implementation to ensure it is in line with your understanding of how the new system should work.

@erikssonpatrick I need your help to understand whether or not the radar tests and implementation comply with your understanding from ARTS2.

Generally, I am also a bit unhappy with how many WSVs were added, but I do not have the experience required with radar stuff to make a class of this I am happy with (i.e., a RadarSensor class).