Ability to scale DAGMC meshes after reading them into AEGIS

[Waqar-ukaea]

Sometimes the meshes I get access to are scaled in cm or mm when the eqdsks are typically in m. It's useful to have the ability to scale these meshes into m to match the equilibrium.

[Waqar-ukaea]

Copied from comment in issue #42:

DAG->get_coords(arrayOfCoords, ...);
for (auto &coord:arrayOfCoords)
{
   coord = coord*scalingFactor
}
DAG->set_coords(arrayOfCoords, ...);

I could make this more general by writing a function that scales for different length scales appropriately but the core of the function should be something like the above.

I think that scaling the coordinates of the nodes should be all I need to do and the connectivity information should be correctly retained (since it's a uniform scaling across each dimension).