Improved model render usability

[sgpearse]

Model files almost always have different origins and scales than a loaded dataset, making them either too small to see and/or they get rendered nowhere near the dataset domain. This makes it a guessing game on how to translate and scale a given model to render it, no less find where the model is being rendered.

Suggestions:

1. Automatically scale the model to be comparable to the domain size and let the user scale up or down once they can see it
2. Set the origin of the model renderer to the origin of the dataset
3. Allow the user to use Box manipulators to translate and scale the object.

Reported raised user rfaiza here: https://vapor.discourse.group/t/issues-with-importing-3d-model-into-vapor/428/3