Make setting beam angle / beam edge part of the fixture

If we want to have different types of conventional fixtures in our rig display, we have to create a new type.  IE I make a copy of dimmer, name it Fresnel, and set the Fresnel physical model for that new fixture.

It would be convenient if we could set a default Beam / edge for that fixture.  That way I could model a S4 50Degree, S4 36 degree, etc  It would save a small bit of work for me.