Materials item in 3D context menu

Currently we have 'Edit material' on the context menu with 3D. This will open the first material of the 3D model in question.

Model can have multiple materials attached to it and user wants to see those easily.

Change 'Edit material' item to menu item similar to 'Arrange' menu item and use naming 'Materials'. 

When user selects the 'materials', a fly-out menu appears and lists all the materials this model has attached. 

When item on the list of materials is hovered, a sub-menu to edit or remove appears.

If user chooses edit , DS will open Material Editor view.