Add binding to OpenGl image structures and atomic operations

A common use case in CAD applications is the heavy usage of transparent objects. A common approach to Order Independent Transparency is the usage of a so called A-Buffer using the OpenGL image data structure.

A very nice introduction for this approach might be found in:

https://stackoverflow.com/q/16934695/5762796

This mentioned solution for Order Independent Transparency is memory and time efficient and requires just two passes. Older approaches as Depth Peeling are quite more complex and requires many passes, depending on the scene complexity.

Now, Qt3D lacks the support for `QParameter` connecting Image structures, and also atomic operations, to the fragment shaders, especially the OpenGL command glBindImageTexture is not yet implemented in Qt3D.

In order to cover more uses cases, including CAD applications, it would be a great benefit to support the OpenGL image structure.