Make the material editor header dockable

The material editor header consists of the preview, shape button, background color button, material name, and material type.

The user should be able to dock/undock this header to the view .

In the case that it's docked, it should stay at the top of the view and below the editor toolbar while scrolling the material properties.

When it's not docked, it should be at the top of the scroll area, and it might be hidden if the user scrolls down.