Add a button to only bake shape keys

[imagitama]

Baking shape keys is a very useful feature that gives players a quick FPS boost.

To use it in CATS means you have to also bake/atlas/do heaps more optimisations when at the end of the day some people only want to bake their shape keys. Tested in the development branch in Blender 3.1.

Can you please add a button to bake the shape keys (ie find all shape keys with _bake suffix and bake them).

[feilen]

Should be fairly easy, don't see why not!