Support texture baking (uv_camera)

[JenusL]

Arnold 5.2 has a new camera for baking textures called uv_camera. We should add that to SItoA.

[sjannuz]

With care. uv_camera it's not like the other ones and should not be exposed as such. It should be leveraged in a render-to-texture utility, as in the other DCCs.

[JenusL]

Ok thanks for the info. Will hold off on this one then.