Make use of the new BoundingVolume, Extension, Tile, Tileset and ThreeDTilesNotion classes

[robyngit]

In merge request #111, Oslandia added many of the classes and functionality that we created in the viz-3dtiles repo. We should consider making use of the classes and features that are now native to py3dtiles, and consider deprecating the use of viz-3dtiles in our workflow. This will require investigating whether or not the py3dtiles update includes all of the features we created in viz-3dtiles. If not, we have the option of either continuing to use those features via viz-3dtiles, OR moving those extra features into our version of py3dtiles.