Swap names for Vis/IR default natural_color and natural_color_sun composites

[djhoese]

The builtin composite for natural_color does not apply the sunz_corrected modifier to its inputs. To get those applied you have to ask for natural_color_sun. My current issue is that it has become fairly standard for natural_color in sensor-specific configs to be the sunz_corrected version.

As it is right now a sensor will see natural_color and natural_color_sun as two types of composites that could be generated, but they are actually the same thing.

Thoughts?

[pnuu]

The SZA-cosine corrected version is the one we at FMI have in production. Also, we have them defined in local configs so I don't mind the change. As a disclaimer I should note that all the composites we use are locally defined, and we never use the built-in composites directly. And, frankly, I think no one should use them that way in operational context. Ever.

[djhoese]

Looks like this was closed in #1066.