Improve the rendering performance of rgg core and assy

This commit improves the rendering performance by reducing the number of prototypes passed into vtkGlyph3DMapper as under the hood vtkGlyph3DMapper will generate one vtkOpenGL3DMapper per prototype. For large reactor model, there might be hundred of mappers running at the same time. The old logic is that for each sub auxgeoms in pins and ducts, we glyph all of them. Now the new logic is to use unit geometries and scale&&transformation&&color feature int vtkGlyph3DMapper so that a single unit geometry can be reused by multiple subpin and subducts. Generally speaking it reduces the number of prototypes by at least one maginitude.

See details in SMTK issue #259.

It also fixes the misaglined combobox in EditPin and EditPin operator view.