Bforartists: Compositor - Add icons to nodes headers

[Draise14]

Request

The shader editor now has icons in the headers of the nodes in the editor. Thanks @iyadahmed ! But now the compositor also has the iconized toolshelf but no icons in the header.

Task

Do the same from the Shader Editor to the Compositor Editor

Note

This is similar to task #1609

[iyadahmed]

should the preview button icon be replaced with the icon, it doesn't feel right having different icons for same functionality
many compositor nodes have an icon in the header that toggles node preview
the question is, should they be kept and have two icons, or replace it, it would still function the same

[ReinerBforartists]

Hm. One icon makes more sense. On the other hand, having a dedicated preview button makes also sense. I keep it in your hands, im am green with both solutions. With a tendency to keep both buttons.

[ReinerBforartists]

Ah, the reason why i think that two icons are better here is that you can distinguish then that this special node has a preview window that can be hidden, and potentially is.

[iyadahmed]

Agree with two icon solution, currently it is set to material icon, maybe we could change this in future, would be another task

[ReinerBforartists]

Yes. Please make another task for it :)