Support zoom on right mouse button click + mouse move

[fedorov]

This would be convenient and consistent with the default behavior we have in OHIF Viewer.

@igoroctaviano says we may have had a mode where user could define a region and zoom into that region.

We should look into the behavior of other SM tools and conventions.

It might also be helpful to have these configurable by the user.

In summary, we need to have more discussions here before implementing any changes.