Rename the Corona shaders

[Cinemike]

Currently there is a random mix. We have "Color Mix" and "Corona Color Correct". Either remove "corona" from all shader names or add it to every single one. Stay consistent.

[Beanzvision]

I also agree, as these are already housed under the Corona menu, the full naming is probably not needed. Let's see how the devs feel on the topic ;)

[Nejc Kilar]

For what its worth, +1 from me :)