evas: move the type and enum of Evas_3D into the unstable part of the API.

evas: move the type and enum of Evas_3D into the unstable part of the API.

I am concerned that we do duplicate the color format of a texture insteed
of reusing the colorspace enum from Evas (that already exist). I believe
this is a side effect of not using Evas_GL_Image for texture.

This let me think that I wont allow this API out of BETA until we reduce
duplication by using Evas_GL_Image as it seems it will also impact the
public API of Evas_3D.