Implement a way to resize a geometry

[amereghe]

It would be great to implement the mean to rescale entirely a geometry.

The user should specify:

• a center (3 coordinates xyz), around which re-scaling is applied symmetrically;
• a scaling array, expressing by how much the 3 dimensions should be scaled. The array should state either the scaling factors or the new dimensions.

Think, for instance, about scaling the model of the T175 flask to get all the others.