Rhinoceros_Toolkit: Converts for NurbsSurfaces with trims

[kThorsager]

Description:

NurbsSurfaces with outer trims.

If a NurbsSurface outer trim has a Ellipse or Circle as its outer surface trim it can't be converted back to Rhino after being in the BHoM.

Fairly sure it's because rhino checks the trims for closeness, but ellipses and circles don't have start/endpoints where the trim expects it and hence fails.

i.e. Rhino sends the trim over as nurbs curve, BHoM makes it into a Circle/Ellipse and loses the start/end, BHoM sends over the curves, Rhino checks if the curve is closed and can't find them.

Think always keeping trims as Nurbs should fix this?
@epignatelli

Steps to reproduce:

see test file

Expected behaviour:

I'd like to convert back and forth between Rhino and BHoM

Test file(s):

https://burohappold.sharepoint.com/:u:/s/BHoM/EZXSnjChE6hJiaKi-ZfpHmMBACb1U_cZjMPaZ9OhUjGrOA?e=GRjPNL

[michaelhoehn]

I can have a look at this one in the coming 7.1 milestone.