Some more clean-up in the animator dockers.
Note that some icons don't load properly, according to somsubhra that happens because those icons are not loaded in Krita first.
That might be because we are sharing KisView2.. and so problem should be solved after the mvc merge, once we load the dockers in krita itself.

Also hides a button that is actually useless and dangerous.

TODO:
At least add icons for "add keyframe", "add empty frame", "delete frame" .
If possible create new dark/light icons instead of colored ones for other icons.