Subdivide cells

The filter utilizes three different subdivision algorithms to subdivide a mesh’s cells:

• butterfly - Butterfly subdivision algorithm
• loop - Loop subdivision algorithm

The running example can be found in the repository

fn main() -> TessResult<()> {

    let ico = mesh::shape::icosahedron::Icosahedron::create(Vertex::default(), 0.2,  Attributes::default());
    let ico_b1 = ico.subdivide_by_loop(1)?;
    let ico_b2 = ico.subdivide_by_butterfly(1)?;
    Ok()
}