0032139: Visualization - support single-precision floating point data within Poly_Tri...

0032139: Visualization - support single-precision floating point data within Poly_Triangulation

Introduced NCollection_AliasedArray collection defining a general byte array
to be aliased as array of elements of mutable type.

Poly_ArrayOfNodes specializes this interface for collecting 2d/3d points with single/double precision.
Poly_Triangulation relies on this new class for definition of 3D nodes and UV coordinates
using gp_Pnt and gp_Pnt2d by default as before.

RWGltf_CafReader now fills in triangulation using single precision by default (as stored in the file).