Sofa update

* Made sofas colorable by RGB rather than fixed onto the icon. Currently colors can't be changed in any way ingame or through code (will fix through code in any minute). Ingame changing will be for some other PR.
For mappers: Sofa types are still the same, they all look like grey sofas in-editor but will have their correct colors ingame.

* Made sofa's armrest be ontop of mobs buckled to the sofa