List indexing polygon conversion

[kevyuu]

Create a method in polygon manipulator that turn any non triangle list geometry to triangle list geometry.

[devshgraphicsprogramming]

Rember to build or Use CI to check before labelling things as merge ready

C:\mount\nabla\include\nbl/asset/utils/CPolygonGeometryManipulator.h(105): error C3487: 'nbl::asset::IBuffer::E_USAGE_FLAGS': all return expressions must deduce to the same type: previously it was 'nbl::core::bitflag<nbl::asset::IBuffer::E_USAGE_FLAGS>'

(also whenever you actually have a test/example run it cause CI doesn't run tests yet - just checks buildability).