Add options to bulk material menuitem

[nukeandbeans]

Adding the ability to choose default/instance options for the menuitem SabreCSG > Create Material(s) ... would allow a bit more flexibility when creating a bunch of transparent materials.

This was suggested over on discord by dsc

My own personal addition to this would allow checking the texture name for an arbitrary user-defined flag, e.g. _masked, etc. and applying the proper material properties that way.