Modernize camera APIs

[jacomyal]

There are some oldies in the camera APIs, such as:

• optional callbacks, but outside the options object, for the animation methods
• weird old-school polymorphisms (like factorOrOptions?: number | (Partial<AnimateOptions> & { factor?: number }) for animatedUnzoom and animatedZoom)
• weird methods namins (isAnimated, unzoom things...)

For the v4, it might be nice to go upgrade these APIs, so that they feel a bit more modern.