Create Surface Asset that contains all Surface Properties

[LogicalError]

This asset would contain:

• Material
• PhysicMaterial
• Renderable/Collidable etc. flags (.. essentially a ChiselBrushMaterial)
• additional payload data (somehow) such as sound effects

This would allow us to drag & drop all surface properties together all at once

[LogicalError]

We should probably turn ChiselBrushMaterial into an asset (we can discuss a better name) and modify the UX so that it no longer looks like that each polygon has it's own settings. All polygons would reference a ChiselBrushMaterial instead. So if someone wants to change the "renderable" property, they'd have to create a new asset.