Suggestion : add a method to zoom on a given position

[mgermerie]

Discussing with @ftoromanoff, we figured it could be interesting to add a method that users could call in order to zoom in a given position. This method - which we could name for instance zoomInTowardPosition - would take a world position as a parameter and would trigger a zoom in toward this given position when called. This would allow users to bind custom buttons to zoom actions.
An equivalent method would be added for zoom out.
Otherwise, we could add a single method which would take two parameters : a target position for the zoom and a number. According to the sign of the number, the performed zoom could be zoom in or zoom out.

I believe the adequate place for such a method would be in controls (mainly PlanarControls since the zoom in GlobeControls is toward the center of the screen, but perhaps we could implement it in globe too).

What do you think @gchoqueux ?

[gchoqueux]

CameraUtils.animateCameraToLookAtTarget look like this feature?

[gchoqueux]

could you try CameraUtils.getCameraTransformOptionsFromExtent?